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IVR design practices

Verified 2026-09-25 · 60 sources · tier 1–2

Interactive voice response (IVR) and auto attendant architectures rely on menu structuring, timing controls, and fallback routing across telephony platforms 53​21. Standards and regulatory requirements define baseline accessibility behaviors, while specific platforms impose architectural rules for voice navigation, error management, and session lifecycles 22​8.

Microsoft call routing best practices state that auto attendant menus should be limited to 5 or fewer items to prevent caller recall issues, with nested auto attendants employed when additional options are needed 53. Microsoft also advises reviewing existing incoming call volume and types to place the most frequent options first in the menu structure 46. Menu prompts should use terminology callers understand rather than internal operational names 44. Prompt phrasing should state the service before the key (For Sales press 1) rather than the key before the service (Press 1 for Sales) 54. Frequent, basic administrative inquiries—such as operational hours, locations, or website addresses—can be handled through recorded announcements rather than routed transfers 52. When menu modifications occur, Microsoft advises against frequent routing changes and recommends notifying callers of prompt updates during the first 30 days 45.

Microsoft Teams Auto Attendants and Call Queues

Teams auto attendant menu options can be mapped to keypad keys 0–9, *, and # 37. Key assignments do not need to be contiguous; for example, an administrator can map keys 0, 1, and 3 while leaving 2 unassigned 38. When Voice inputs is enabled, menu selections operate as speech-recognition keywords, allowing a caller to press 2, say "two", or utter the designated voice command like "Sales" 42. However, selecting a language lacking speech recognition disables voice inputs entirely and restricts dial by name to keypad DTMF entry; several text-to-speech (TTS) languages, including German (Germany) and Korean, lack speech recognition 41. Teams auto attendant and call queue TTS does not translate input text, requiring prompts to be written directly in the targeted language 55.

Greetings in Teams auto attendants can be uploaded as WAV, MP3, or WMA files up to 5 MB, or generated via TTS up to 1,000 characters 36. If business hours remain unconfigured, the default schedule routes business-hours flows from 09:00 to 17:00 and after-hours flows outside those times every day of the week, including weekends 33. Microsoft recommends against routing direct service numbers to Teams call queues unless staffed 24/7, because call queues lack native after-hours or holiday handling; numbers should instead route to an auto attendant that redirects to the queue during business hours 43.

  • A single call is limited to a maximum of 25 transitions across auto attendants and call queues before being disconnected; returning to a main menu following an announcement or repeat option counts against this limit 32.
  • A single auto attendant supports only one dial-by method, requiring separate auto attendants if both dial by name and dial by extension are needed 40.
  • When dial keys are mapped on an auto attendant, Microsoft recommends setting Directory search to None, as dial keys take precedence and can transfer a caller before a name or extension entry finishes; directory search should instead reside on a separate auto attendant reached via a designated menu key 35.
  • Newly provisioned users may take up to 36 hours to appear in dial-by-name directories 34.
  • The auto attendant Operator destination handles calls when no input is entered or an error occurs, but the Operator feature and spoken command are active only if an Operator key is explicitly mapped in the menu 39.

Teams call queues provide default, royalty-free music on hold, while custom audio uploads require the organization to clear music rights 49. Queues hold a default of 50 waiting calls, adjustable between 0 and 200 (a setting of 0 prevents greetings from playing), and call timeouts can range from 0 seconds to 45 minutes 50. The service level threshold can be configured from 0 to 40 minutes (2,400 seconds) and should sit below the call timeout (though not enforced), but service level metrics are currently absent from historical reporting 51.

Queue callback is offered only after the music on hold finishes its playback loop 48. As a result, timeout parameters must accommodate queue eligibility, the full music loop, the request exchange, and agent answering; because default queue music lasts 2 minutes, a configuration with a 60-second eligibility rule and a 120-second timeout prevents callback from ever being offered 48. Callback eligibility requires an inbound caller ID that is publicly dialable, non-premium, and in E.164 format while not actively presenting to an agent; certain North American prefixes, including toll-free codes, are disqualified 47.

Webex Calling Auto Attendants

Webex Calling auto attendants permit menu keys to trigger an announcement, transfer with or without prompt, transfer to an operator, transfer to voicemail, dial by name, dial by extension, exit the menu, or remain unassigned ("Not Used") 59. Callers can also be permitted to dial an internal extension at any point without requiring an explicit menu entry 58.

Custom greeting uploads in Webex Calling must be formatted as 8 or 16 kHz, 8 or 16 bit mono audio in u-law, A-law, or PCM format, with file sizes capped at 2 MB (approximately 4 minutes) 57. The no-input timer accepts values between 1 and 60 seconds, and menus can be configured to repeat between 1 and 3 times, or not at all 60.

Amazon Connect and Lex Flows

The Amazon Connect Get customer input block accepts only single digits 0-9, # and *; multi-digit entries such as card numbers need the Store customer input block 10. The Get customer input DTMF timeout is configured statically between 1 and 180 seconds, measuring the duration until the caller inputs the first digit 9. The block branches to Timeout if no input is detected within the window, Default if the input fails to match defined conditions or intents, and Error on block failures or unfulfilled intents 8. AWS notes that if a caller types ahead across a Transfer to flow block into a Store customer input block, digits pressed before the next prompt starts can be dropped 7.

When integrating Amazon Lex voice input within Connect:

  • Default speech timeout parameters include a 12-second maximum speech duration (with a platform ceiling of 55 seconds, above which contacts take the Error branch), a 3-second start silence threshold, and a 0.6-second end silence threshold 14.
  • For keypad inputs handled by a Lex bot, the default termination character is #, the default deletion character is *, and the inter-digit timeout defaults to 5 seconds; AWS notes callers who are not prompted to finish with # wait 5 seconds before processing continues 13.
  • Barge-in for Amazon Lex (V2) bots is enabled globally by default, while for Amazon Lex (Classic) it is disabled by default and must be enabled with a session attribute that does not control DTMF barge-in 12.

AWS prescriptive guidance advises encapsulating recurring logic (such as payment processing or post-call SMS) into reusable flow modules rather than duplicating logic across applications 17. Backend integrations using AWS Lambda enable self-service with increased containment rates, though AWS prescriptive documentation provides no specific containment formula or target 15. The prescriptive guide covering modular IVR architecture focuses strictly on DTMF flows and flow modules, placing Amazon Lex natural-language capabilities out of scope 16.

For queue handling, Amazon Connect documentation includes a sample interruptible queue flow that breaks looping audio every 30 seconds to prompt the caller to press 1 to request a callback or press 2 to maintain queue position 11. Abandonment metrics treat disconnects occurring while waiting in queue prior to agent connection as abandoned, but contacts placed in a callback queue are excluded from abandonment counts 6. The abandonment rate represents contacts abandoned divided by contacts queued, multiplied by 100; this metric displays as 0 when grouped by routing profile 5.

Automated flow validation can be performed using Amazon Connect Testing and Simulation, which runs simulated caller inputs (DTMF or text utterances) and verifies event sequences against expected targets 20. Testing is subject to platform limits: a maximum of 5 concurrent tests, up to 100 queued executions, and a 5-minute timeout per test run 18. AWS warns that simulated test contacts not disconnected prior to a queue transfer can route to live agents, recommending early call termination or dedicated test queues 19.

Conversational Agent Handling and Outcomes

In conversational platforms, Google Dialogflow CX voice design guidance recommends allowing a maximum of 3 consecutive no-match or no-input events per page, escalating to a live representative on the third failure 31.

Copilot Studio classifies each engaged session as Resolved, Escalated or Abandoned, and sessions that never become engaged are Unengaged 28. A session is classified as Escalated as soon as an Escalate topic is triggered or a Transfer to agent node executes, regardless of whether a live agent connects 27. Escalations are logged as System intended, System unintended, or User requested 27. An engaged session is counted as Abandoned if it times out after 30 minutes of inactivity without resolving or escalating 26. While standard Copilot Studio sessions time out after 30 minutes of inactivity, agents deployed to the Telephony channel time out 3 minutes after an End Conversation event 29. Test panel interactions within the Copilot Studio authoring canvas are excluded from analytics metrics 30.

Standards and Regulatory Requirements

VoiceXML 2.0 was established as a W3C Recommendation on 16 March 2004 56.

Federal accessibility requirements govern interactive voice and automated attendant implementations in the United States:

  • Revised Section 508 Standards / Section 255 Guidelines provision 412.8.4 requires auto-attendant, interactive voice response, voicemail, and caller identification systems to support operation with a TTY where provided 1.
  • Provision 407.5 mandates that where a timed response is imposed, the user must receive visual and audible or touch alerts and be provided an opportunity to indicate that more time is needed 3.
  • Provision 412.5 Real-Time Text Functionality in the Revised 508 Standards is marked [Reserved] and currently sets no RTT requirement 2.
  • Under 47 CFR 6.3, the FCC Section 255 definition of accessible includes operation without time-dependent controls: at least 1 mode that needs no response time or lets the user bypass or adjust response time over a wide range 21.
  • 47 CFR Part 7 covers access to voicemail and interactive menu services and equipment by people with disabilities, defining an interactive menu under 7.3(e) as a feature that lets a service provider or CPE operator transmit information to a caller in visual and/or audible format 23.
  • Under 47 CFR 7.5, equipment manufacturers and telecommunications service providers must make voicemail and interactive menu functions accessible to and usable by individuals with disabilities if readily achievable, and otherwise compatible with peripheral devices or specialised CPE commonly used by people with disabilities 22.

See also

Applicability

Applies to: Microsoft Teams Phone auto attendant, FCC telecommunications equipment, FCC voicemail, AWS Amazon Connect (Connect Customer), Microsoft Teams Phone call queue, Cisco Webex Calling auto attendant, AWS Amazon Connect (Connect Customer) with Amazon Lex, Google Dialogflow CX, Microsoft Copilot Studio, W3C VoiceXML 2.0, US Access Board ICT with two-way voice communication, and US Access Board ICT with operable parts. Deployments: multi-tenant and any. Sources checked 2026-09-25. Revised Section 508 Standards / Section 255 Guidelines provision 412.8.4 applies to voice mail, auto-attendant, interactive voice response, and caller identification systems in the United States 1. Provision 407.5 and provision 412.5 in the Revised 508 Standards apply to implementations requiring timed responses and real-time text in the United States 3​2. 47 CFR 6.3, 47 CFR 7.3(e), and 47 CFR 7.5 govern FCC accessibility obligations for telecommunications service providers and equipment manufacturers in the United States 21​23​22. VoiceXML 2.0 applies as a W3C Recommendation dated 16 March 2004 56.

What remains uncertain

Specific containment calculation formulas and numeric containment benchmarks for AWS Lambda self-service flows are not covered by the sources below. Historical reporting availability schedules for Teams call queue service level threshold metrics are not covered by the sources below. Real-time text (RTT) implementation mandates under Section 508 remain unestablished, as provision 412.5 remains reserved 2.

See also

Related to

Referenced by

  • Five9 IVR and Studio — Vendor-neutral IVR design guidance; this topic covers the Five9-specific IVR script modules and IVA Studio call flows.
  • GoTo Connect — Dial Plan Editor and Conditional Routing node are GoTo Connect's IVR/call-flow surface
  • Zoom Phone call queues and auto receptionists — Vendor-neutral IVR design topic; this packet covers the Zoom Phone auto receptionist and IVR mechanics only. Proposed by this packet; not previously recorded.

Sources

  1. 1
    Revised Section 508 Standards / Section 255 Guidelines provision 412.8.4 requires that, where provided, voice mail, auto-attendant, interactive voice response and caller identification systems be usable with a TTY.
    Revised 508 Standards and 255 Guidelines · 412.8.4 Voice Mail and Other Messaging Systems · Checked 2026-09-25
  2. 2
    Provision 412.5 Real-Time Text Functionality in the Revised 508 Standards is marked [Reserved] and currently sets no RTT requirement.
    Revised 508 Standards and 255 Guidelines · 412.5 Real-Time Text Functionality · Checked 2026-09-25
  3. 3
    Revised Section 508 provision 407.5 requires that where a timed response is required the user be alerted visually and by touch or sound and be given the opportunity to indicate that more time is needed.
    Revised 508 Standards and 255 Guidelines · 407.5 Timed Response · Checked 2026-09-25
  4. 4
    Because Amazon Connect defines abandonment against contacts in queue, callers who hang up inside the IVR before reaching a queue are probably not counted in its abandonment rate and need to be measured separately.inferred
    Metrics definitions in Connect Customer · Contacts abandoned; Abandonment rate · Checked 2026-09-25
  5. 5
    Amazon Connect calculates abandonment rate as contacts abandoned divided by contacts queued, times 100, and shows it as 0 when grouped by routing profile.
    Metrics definitions in Connect Customer · Abandonment rate · Checked 2026-09-25
  6. 6
    Amazon Connect counts a contact as abandoned when the customer disconnects while in queue before being connected to an agent, and contacts queued for callback are not counted as abandoned.
    Metrics definitions in Connect Customer · Contacts abandoned · Checked 2026-09-25
  7. 7
    AWS warns that when a caller types ahead across a Transfer to flow into a Store customer input block, digits entered before the next prompt plays can be dropped.
    Flow block in Connect Customer: Get customer input · Error scenarios · Checked 2026-09-25
  8. 8
    The Amazon Connect Get customer input block routes to Timeout when no input arrives within the timeout, Default when input matches no condition or intent, and Error when the block errors or a Lex intent is not fulfilled.
    Flow block in Connect Customer: Get customer input · Flow block branches · Checked 2026-09-25
  9. 9
    The Amazon Connect Get customer input DTMF timeout is set statically between 1 and 180 seconds and, on voice, measures the wait until the first digit is entered.
    Flow block in Connect Customer: Get customer input · How to configure this block > Configure for DTMF input > Set timeout · Checked 2026-09-25
  10. 10
    The Amazon Connect Get customer input block accepts only single digits 0-9, # and *; multi-digit entries such as card numbers need the Store customer input block.
    Flow block in Connect Customer: Get customer input · Description · Checked 2026-09-25
  11. 11
    The Amazon Connect sample interruptible queue flow interrupts looping queue audio every 30 seconds to offer press 1 to enter a callback number or press 2 to stay in queue.
    Sample interruptible queue flow with callback in Connect Customer · page body (voice channel paragraph and numbered options) · Checked 2026-09-25
  12. 12
    In Amazon Connect, barge-in for Amazon Lex (V2) bots is enabled globally by default, while for Amazon Lex (Classic) it is disabled by default and must be enabled with a session attribute that does not control DTMF barge-in.
    Flow block in Connect Customer: Get customer input · Configure for Amazon Lex input > Barge-in configuration and usage for Amazon Lex · Checked 2026-09-25
  13. 13
    When a Lex bot collects keypad input in Amazon Connect, the default end character is #, the default deletion character is *, and the default inter-digit end timeout is 5 seconds; AWS notes callers not prompted to finish with # wait five seconds.
    Flow block in Connect Customer: Get customer input · Configurable fields for DTMF input; Additional configuration tips · Checked 2026-09-25
  14. 14
    For Amazon Lex voice input in Amazon Connect, the defaults are 12 seconds maximum speech duration (maximum allowed 55 seconds, above which the contact takes the Error branch), a 3-second start silence threshold and a 0.6-second end silence threshold.
    Flow block in Connect Customer: Get customer input · Configure for Amazon Lex input > Configurable time-outs for voice input · Checked 2026-09-25
  15. 15
    AWS prescriptive guidance states that integrating flows with backend systems through AWS Lambda enables self-service with an increased containment rate, but the guide gives no containment formula or target.
    Connect Customer features for IVR applications · AWS Lambda functions · Checked 2026-09-25
  16. 16
    The AWS prescriptive guide on modular IVR design on Connect covers DTMF-style flows and modules and puts Amazon Lex natural-language features out of scope.
    Designing the foundation of a dynamic and modular IVR experience on Connect Customer · Introduction, third paragraph · Checked 2026-09-25
  17. 17
    AWS prescriptive guidance recommends extracting repeated IVR logic such as payment intake or post-transaction SMS into reusable Amazon Connect flow modules instead of duplicating it across applications.
    Connect Customer features for IVR applications · Flow modules · Checked 2026-09-25
  18. 18
    Amazon Connect Testing and Simulation allows 5 concurrent tests and up to 100 executions in the queue, and each test times out after 5 minutes.
    Execute test cases - Connect Customer · Execute test cases > limitations list (Concurrent Test Limit; Test Execution Queue Capacity; Test Duration Limit) · Checked 2026-09-25
  19. 19
    AWS warns that a simulated test contact that is not ended before transfer to a queue may reach a live agent, and recommends ending tests early or substituting dedicated test queues.
    Execute test cases - Connect Customer · Execute test cases > Agent Queue Interaction; Best practice to handle simulated contact in the agent queue · Checked 2026-09-25
  20. 20
    Amazon Connect Testing and Simulation runs automated tests by creating a new contact that simulates caller inputs such as DTMF or text utterances and validates observed events against expected ones.
    Execute test cases - Connect Customer · Execute test cases, first paragraph · Checked 2026-09-25
  21. 21
    The FCC Section 255 definition of accessible in 47 CFR 6.3 includes being operable without time-dependent controls: at least one mode that needs no response time or lets the user bypass or adjust response time over a wide range.
    47 CFR 6.3 - Definitions · 47 CFR 6.3(a)(1)(viii) · Checked 2026-09-25
  22. 22
    Under 47 CFR 7.5, equipment manufacturers and telecommunications service providers must make voicemail and interactive menu functions accessible to and usable by individuals with disabilities if readily achievable, and otherwise compatible with peripheral devices or specialised CPE commonly used by people with disabilities.
    47 CFR 7.5 - General obligations · 47 CFR 7.5(a)(1), (a)(2), (b)(1), (b)(2) · Checked 2026-09-25
  23. 23
    47 CFR Part 7 covers access to voicemail and interactive menu services and equipment by people with disabilities, and 7.3(e) defines an interactive menu as a feature that lets a service provider or CPE operator transmit information to a caller in visual and/or audible format.
    47 CFR 7.3 - Definitions (voicemail and interactive menu access) · 47 CFR 7.3(e) · Checked 2026-09-25
  24. 24
    Because 47 CFR 7.5 puts its duties on manufacturers and telecommunications service providers, an ordinary business that runs its own IVR is probably not directly bound by Part 7, although other accessibility law may apply.inferred
    47 CFR 7.5 - General obligations · 47 CFR 7.5(a) and (b) · Checked 2026-09-25
  25. 25
    The sources in this packet define abandonment and self-service outcomes in incompatible ways (Amazon Connect abandonment is in-queue disconnection; Copilot Studio abandonment is a 30-minute engaged-session timeout), so no single cross-vendor containment or abandonment rate definition can be assumed.inferred
    Monitor conversational agents - Microsoft Copilot Studio · Conversation outcomes (Abandoned row), compared with aws-connect-metrics-definitions Contacts abandoned · Checked 2026-09-25
  26. 26
    Copilot Studio counts an engaged session as Abandoned when it times out after 30 minutes without reaching a resolved or escalated state.
    Monitor conversational agents - Microsoft Copilot Studio · Effectiveness > Conversation outcomes (Abandoned row) · Checked 2026-09-25
  27. 27
    Copilot Studio counts a session as Escalated when the Escalate topic triggers or a Transfer to agent node runs, whether or not the conversation actually reaches a live agent, and splits escalations into System intended, System unintended and User requested.
    Monitor conversational agents - Microsoft Copilot Studio · Effectiveness > Conversation outcomes (Escalated rows) · Checked 2026-09-25
  28. 28
    Copilot Studio classifies each engaged session as Resolved, Escalated or Abandoned, and sessions that never become engaged are Unengaged.
    Monitor conversational agents - Microsoft Copilot Studio · Effectiveness > Conversation outcomes (outcome table) · Checked 2026-09-25
  29. 29
    Copilot Studio conversations time out after 30 minutes of inactivity in general, but for agents published to the Telephony channel they time out 3 minutes after an End Conversation event.
    Monitor overview - Microsoft Copilot Studio · Conversational sessions only · Checked 2026-09-25
  30. 30
    Copilot Studio analytics do not include activity from testing an agent in the Copilot Studio test panel.
    Monitor overview - Microsoft Copilot Studio · Introduction > Note · Checked 2026-09-25
  31. 31
    Google's Dialogflow CX voice design guidance recommends a maximum of three no-match or no-input events per page, escalating to a human agent on the third.
    Voice agent design best practices (Dialogflow CX) · No-match and no-input handling section · Checked 2026-09-25
  32. 32
    A single call can make at most 25 transitions through Teams auto attendants and call queues and is disconnected after the 25th; returning to the same auto attendant's main menu after an announcement or a repeat option counts as a transition.
    Design - Call flows for voice applications - Microsoft Teams · Call routing best practices > Important · Checked 2026-09-25
  33. 33
    If business hours are not changed on a Teams auto attendant, the business-hours call flow runs 09:00-17:00 and the after-hours flow runs outside those hours every day of the week, including weekends.
    Setup - Auto Attendant - Microsoft Teams · Advanced setup > Step 2: Call handling hours > Business and after hours · Checked 2026-09-25
  34. 34
    A new user can take up to 36 hours to appear in a Teams auto attendant dial-by-name directory.
    Setup - Auto Attendant - Microsoft Teams · Advanced setup > Step 6: Dial scope > Note · Checked 2026-09-25
  35. 35
    Microsoft recommends setting Directory search to None on a Teams auto attendant that has dial keys assigned, because dial keys are matched first and a caller can be transferred before finishing a name or extension; a separate auto attendant reached by a dial key is recommended for directory search.
    Setup - Auto Attendant - Microsoft Teams · Advanced setup > Step 3 > Directory search · Checked 2026-09-25
  36. 36
    Teams auto attendant greetings can be an uploaded WAV, MP3 or WMA file of no more than 5 MB, or typed text-to-speech of up to 1,000 characters.
    Setup - Auto Attendant - Microsoft Teams · Advanced setup > Step 3: Business-hours call flow > Greeting options · Checked 2026-09-25
  37. 37
    Teams auto attendant menu options can be mapped to the 0-9, * and # keys on the telephone keypad.
    Setup - Auto Attendant - Microsoft Teams · Advanced setup > Step 3: Business-hours call flow > Set menu options · Checked 2026-09-25
  38. 38
    Teams auto attendant key mappings do not have to be contiguous; a menu can use keys 0, 1 and 3 while leaving 2 unused.
    Setup - Auto Attendant - Microsoft Teams · Advanced setup > Step 3 > Set menu options · Checked 2026-09-25
  39. 39
    A Teams auto attendant sends callers to the configured Operator when they make no menu selection or when a call processing error occurs, but the Operator feature and the spoken Operator command are only enabled if an Operator key is also mapped in the menu.
    Setup - Auto Attendant - Microsoft Teams · Advanced setup > Step 1: General info > Operator (optional); Step 3 > Set menu options · Checked 2026-09-25
  40. 40
    A single Teams auto attendant supports only one dial-by method, so offering both dial by name and dial by extension requires separate auto attendants.
    Design - Call flows for voice applications - Microsoft Teams · Auto Attendants > Note · Checked 2026-09-25
  41. 41
    Choosing a Teams auto attendant language that lacks speech recognition disables voice inputs and restricts dial by name to keypad (DTMF) entry; many TTS languages such as German (Germany) and Korean are marked without speech recognition.
    Setup - Auto Attendant - Microsoft Teams · Advanced setup > Step 1: General info > Language (supported languages table and following Note) · Checked 2026-09-25
  42. 42
    When Voice inputs is enabled on a Teams auto attendant, menu options become speech-recognition keywords, so a caller can press 2, say two, or say the option's voice command such as Sales.
    Setup - Auto Attendant - Microsoft Teams · Advanced setup > Step 1: General info > Voice inputs; Step 3 > Set menu options (Voice command) · Checked 2026-09-25
  43. 43
    Microsoft advises against assigning service numbers directly to Teams call queues unless the queue is staffed 24/7, because call queues have no separate after-hours or holiday handling; the number should go on an auto attendant that redirects to the queue during business hours.
    Design - Call flows for voice applications - Microsoft Teams · Call routing best practices, bullet 3 · Checked 2026-09-25
  44. 44
    Microsoft advises using terminology callers understand rather than internal names in menu prompts.
    Design - Call flows for voice applications - Microsoft Teams · Call routing best practices, bullet 7 · Checked 2026-09-25
  45. 45
    Microsoft advises avoiding frequent routing changes and, when auto attendant menu options change, telling callers so in the prompts for the first 30 days.
    Design - Call flows for voice applications - Microsoft Teams · Call routing best practices, bullet 8 · Checked 2026-09-25
  46. 46
    Microsoft advises analysing the types and frequency of incoming calls on the existing system and putting the most common options first in the menu.
    Design - Call flows for voice applications - Microsoft Teams · Call routing best practices, bullets 1 and 2 · Checked 2026-09-25
  47. 47
    To be eligible for Teams call queue callback the caller's inbound number must be publicly dialable, nonpremium and in E.164 format, and the call must not be presenting to a representative; certain North American prefixes, including toll-free codes, are excluded.
    Setup - Call Queue - Microsoft Teams · Advanced setup > Step 5: Callback (eligibility paragraph and North America Note table) · Checked 2026-09-25
  48. 48
    Teams call queue callback is offered to eligible callers only after the music on hold finishes playing, so the call timeout must be long enough for the caller to become eligible, the music to finish, the request, the wait for a representative, and the answer; with the default music, which is two minutes long, a 60-second eligibility and a 120-second timeout means callback is never offered.
    Setup - Call Queue - Microsoft Teams · Advanced setup > Step 5: Callback > Callback and call queue timeouts · Checked 2026-09-25
  49. 49
    Teams call queues provide default music on hold that is free of royalties payable by the organisation; if a custom audio file is uploaded the organisation is responsible for clearing its rights.
    Setup - Call Queue - Microsoft Teams · Advanced setup > Step 2: Greeting and music · Checked 2026-09-25
  50. 50
    A Teams call queue holds a default maximum of 50 waiting calls, configurable from 0 to 200 (at 0 the greeting cannot play), and its call timeout can be set from 0 seconds to 45 minutes.
    Setup - Call Queue - Microsoft Teams · Advanced setup > Step 6: Exception handling > Overflow; Call timeout · Checked 2026-09-25
  51. 51
    The Teams call queue service level threshold can be set from 0 to 40 minutes (2,400 seconds), should be below the call timeout although this is not enforced, and service level metrics are not currently available in historical reporting.
    Setup - Call Queue - Microsoft Teams · Advanced setup > Step 1: General info > Set the Service level threshold (optional) · Checked 2026-09-25
  52. 52
    Microsoft suggests answering frequent basic-information requests such as business hours, location or website with recorded auto attendant messages.
    Design - Call flows for voice applications - Microsoft Teams · Call routing best practices, bullet 4 · Checked 2026-09-25
  53. 53
    Microsoft's call routing best practices say to keep auto attendant menus to five or fewer items because callers have trouble remembering more, and to use nested auto attendants when more options are needed.
    Design - Call flows for voice applications - Microsoft Teams · Call routing best practices, bullet 5 · Checked 2026-09-25
  54. 54
    Microsoft advises stating the service before the key (For Sales press 1) rather than the key before the service (Press 1 for Sales).
    Design - Call flows for voice applications - Microsoft Teams · Call routing best practices, bullet 6 · Checked 2026-09-25
  55. 55
    Teams auto attendant and call queue text-to-speech does not translate; prompt text must be entered in the selected language.
    Setup - Auto Attendant - Microsoft Teams · Advanced setup > Step 1: General info > Language (paragraph after Note) · Checked 2026-09-25
  56. 56
    VoiceXML 2.0 became a W3C Recommendation on 16 March 2004.
    Voice Extensible Markup Language (VoiceXML) Version 2.0 · Document header (Status of this document) · Checked 2026-09-25
  57. 57
    Webex Calling auto attendant custom greetings must be 8 or 16 kHz, 8 or 16 bit mono, u-law, A-law or PCM audio, with a maximum file size of 2 MB (about 4 minutes).
    Manage auto attendants · Greeting configuration (custom greeting audio requirements) · Checked 2026-09-25
  58. 58
    Webex Calling auto attendants can let callers dial an extension at any time without a dedicated menu item.
    Manage auto attendants · Extension dialing setting · Checked 2026-09-25
  59. 59
    Webex Calling auto attendant menu keys can be set to play an announcement, transfer with or without prompt, transfer to operator, transfer to voicemail, dial by name, dial by extension, exit menu, or Not Used.
    Manage auto attendants · Auto attendant menu key actions (business hours and after hours menu configuration) · Checked 2026-09-25
  60. 60
    The Webex Calling auto attendant no-input timer accepts 1 to 60 seconds, and the menu can be set not to repeat or to repeat between 1 and 3 times.
    Manage auto attendants · Menu timeout behaviour · Checked 2026-09-25

Documents

tier 1 standards and regulators

47 CFR 6.3 - Definitions

Cornell Legal Information Institute (republishing eCFR) · accessed 2026-09-25

tier 1 standards and regulators

47 CFR 7.3 - Definitions (voicemail and interactive menu access)

Cornell Legal Information Institute (republishing eCFR) · accessed 2026-09-25

tier 1 standards and regulators

47 CFR 7.5 - General obligations

Cornell Legal Information Institute (republishing eCFR) · accessed 2026-09-25

tier 1 standards and regulators

Revised 508 Standards and 255 Guidelines

U.S. Access Board · 2018-01-22 · accessed 2026-09-25

tier 1 standards and regulators

Voice Extensible Markup Language (VoiceXML) Version 2.0

W3C · 2004-03-16 · accessed 2026-09-25

tier 2 current vendor documentation

Connect Customer features for IVR applications

Amazon Web Services (AWS Prescriptive Guidance) · accessed 2026-09-25

tier 2 current vendor documentation

Design - Call flows for voice applications - Microsoft Teams

Microsoft · 2026-08-31 · accessed 2026-09-25

tier 2 current vendor documentation

Designing the foundation of a dynamic and modular IVR experience on Connect Customer

Amazon Web Services (AWS Prescriptive Guidance) · accessed 2026-09-25

tier 2 current vendor documentation

Execute test cases - Connect Customer

Amazon Web Services · accessed 2026-09-25

tier 2 current vendor documentation

Flow block in Connect Customer: Get customer input

Amazon Web Services · accessed 2026-09-25

tier 2 current vendor documentation

Manage auto attendants

Cisco Systems, Inc. (Webex Help Center) · 2025-12-12 · accessed 2026-09-16

tier 2 current vendor documentation

Metrics definitions in Connect Customer

Amazon Web Services · accessed 2026-09-24

tier 2 current vendor documentation

Monitor conversational agents - Microsoft Copilot Studio

Microsoft · 2026-06-01 · accessed 2026-09-25

tier 2 current vendor documentation

Monitor overview - Microsoft Copilot Studio

Microsoft · 2026-06-01 · accessed 2026-09-25

tier 2 current vendor documentation

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Cite this page

APA

WarmTransfer. (2026, September 25). IVR design practices. WarmTransfer. https://warmtransfer.net/knowledge/ivr-design-practices

BibTeX

@misc{warmtransfer-ivr-design-practices,
  title  = {IVR design practices},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/ivr-design-practices},
  note   = {Verified 2026-09-25}
}