Real-time text and TTY accessibility requirements

See also

Sources

1. 1
   28 CFR 36.303(d)(4) requires a public accommodation to respond to calls from an ADA Title IV relay service in the same manner as other calls.

   28 CFR 36.303 — Auxiliary aids and services (ADA Title III) · § 36.303(d)(4) · Checked 2026-10-02
2. 2
   The DOJ ADA telecommunications rules read (28 CFR 35.161, 35.162 and 36.303(d)) name TTYs, TDDs and relay but not RTT, so whether RTT alone satisfies them depends on the 'equally effective' and 'effective real-time communication' standards rather than any explicit RTT text.inferred

   28 CFR 35.161 — Telecommunications (ADA Title II) · § 35.161(a)-(c); compare § 35.162 and § 36.303(d) · Checked 2026-10-02
3. 3
   28 CFR 35.162 requires telephone emergency services, including 911, to provide direct access to people who use TDDs and computer modems.

   28 CFR 35.162 — Telephone emergency services · § 35.162 · Checked 2026-10-02
4. 4
   Under 28 CFR 35.161(b), a public entity's auto-attendant, voicemail or IVR system must provide effective real-time communication with users of TTYs and all forms of FCC-approved relay, including Internet-based relay.

   28 CFR 35.161 — Telecommunications (ADA Title II) · § 35.161(b) · Checked 2026-10-02
5. 5
   Under 28 CFR 35.161(a), a public entity that communicates by telephone with applicants and beneficiaries must use TTYs or equally effective telecommunications systems with people who are deaf, hard of hearing or have speech impairments.

   28 CFR 35.161 — Telecommunications (ADA Title II) · § 35.161(a) · Checked 2026-10-02
6. 6
   Under 28 CFR 36.303(d)(1), a public accommodation's auto-attendant, voicemail or IVR must provide effective real-time communication with TTY users and users of all FCC-approved relay services, including Internet-based relay.

   28 CFR 36.303 — Auxiliary aids and services (ADA Title III) · § 36.303(d)(1) · Checked 2026-10-02
7. 7
   28 CFR 36.303(d)(3) and (d)(5) let a public accommodation use relay services instead of direct telephone communication and do not require it to use a TTY for calls incident to its operations.

   28 CFR 36.303 — Auxiliary aids and services (ADA Title III) · § 36.303(d)(3) and (d)(5) · Checked 2026-10-02
8. 8
   Cisco's Webex help article on phone accessibility lists acoustic or direct-connect TTY support, HCO/VCO and a G.711 VoIP network requirement for Cisco IP Phone 6800 Series models.

   Phone accessibility features · 6800 series sections > Acoustic coupled TTY and TDD support (handset) · Checked 2026-10-02
9. 9
   Cisco documents IP Phone 8800 Series support for acoustic or direct-connect TTYs and hearing and voice carry over (HCO/VCO) on a VoIP network operating at G.711.

   Accessibility Features for the Cisco IP Phone 8800 Series · Acoustic coupled TTY and TDD support · Checked 2026-10-02
10. 10
    Cisco's phone accessibility pages list 'real-time text transmission over phone lines' under TTY support; in context this describes TTY (Baudot) text carried in G.711 audio, not RFC 4103 RTT as defined in 47 CFR Part 67.inferred

    Accessibility Features for the Cisco IP Phone 8800 Series · Acoustic coupled TTY and TDD support · Checked 2026-10-02
11. 11
    47 CFR 9.10(c) requires covered CMRS providers to be capable of transmitting 911 calls from people with speech or hearing disabilities through means other than mobile handsets, such as TTYs.

    47 CFR part 9 — 911 Requirements · § 9.10(c), first sentence · Checked 2026-10-02
12. 12
    47 CFR 67.1(b) defines a CMRS provider by reference to § 20.18(c), but § 20.18 is reserved in the 2026-09-01 eCFR, so the Part 67 cross-reference appears to point to a section whose substance has moved to Part 9.inferred

    47 CFR Part 67 — Real-Time Text · § 67.1(b); compare 47 CFR 20.18 (source ecfr-47-cfr-20-18) · Checked 2026-10-02
13. 13
    In FCC 25-79 (adopted November 20, 2025) the FCC proposed eliminating the requirement that state TRS programs provide TTY Relay, with a temporary national certification process for states that discontinue it.

    Analog Telecommunications Relay Service Modernization (proposed rule, FCC 25-79) · Supplementary information — TTY-based relay / TTY Relay discussion · Checked 2026-10-02
14. 14
    FCC 25-79 asked whether to authorize TRS Fund support for a nationwide RTT-based relay service, including whether users could direct-dial calls rather than dialling 711.

    Analog Telecommunications Relay Service Modernization (proposed rule, FCC 25-79) · Supplementary information — RTT-based relay discussion · Checked 2026-10-02
15. 15
    In FCC 26-4 (published March 17, 2026) the FCC proposed requiring IP Relay access technology to natively support RTT protocols and user interface features such as character-by-character display, and asked whether an 18- or 24-month transition is appropriate.

    Internet-Based Telecommunications Relay Service Modernization (proposed rule, FCC 26-4) · 'RTT compatibility' discussion, 91 FR 12739-12740 · Checked 2026-10-02
16. 16
    Genesys states that Genesys Cloud does not support direct TTY interactions but does support 711 Telecommunications Relay Service calls.

    Does Genesys support direct TTY (Teletypewriter) interactions? · FAQ answer · Checked 2026-10-02
17. 17
    Under 47 CFR 9.10(c), CMRS providers offering voice over IP facilities need not support 911 access via TTY if they provide 911 access via RTT in accordance with 47 CFR Part 67.

    47 CFR part 9 — 911 Requirements · § 9.10(c), second sentence · Checked 2026-10-02
18. 18
    Manufacturers of devices for CMRS IP voice services that chose RTT over TTY had to implement RTT in newly manufactured equipment by December 31, 2018, subject to achievability.

    Transition From TTY to Real-Time Text Technology (final rule, FCC 16-169) · Summary of Report and Order — implementation timelines (manufacturers) · Checked 2026-10-02
19. 19
    The NG911 rules' definition of 911 traffic in 47 CFR 9.28 covers 911 calls and 911 text messages (as defined in § 9.10(q)(9)) plus location, number and routing data, and does not name RTT separately.

    47 CFR part 9 — 911 Requirements · § 9.28, definition of '911 traffic' · Checked 2026-10-02
20. 20
    Non-Tier I CMRS providers opting for RTT had to support it on all new authorized end user devices by June 30, 2021.

    Transition From TTY to Real-Time Text Technology (final rule, FCC 16-169) · Summary of Report and Order — implementation timelines (non-Tier I) · Checked 2026-10-02
21. 21
    Non-Tier I CMRS providers opting for RTT had an initial compliance deadline of June 30, 2020.

    Transition From TTY to Real-Time Text Technology (final rule, FCC 16-169) · Summary of Report and Order — implementation timelines (non-Tier I) · Checked 2026-10-02
22. 22
    The FCC's TTY-to-RTT transition rules (FCC 16-169) took effect on February 22, 2017.

    Transition From TTY to Real-Time Text Technology (final rule, FCC 16-169) · DATES section · Checked 2026-10-02
23. 23
    The 2017 order requires CMRS providers to deliver RTT to a PSAP in RTT format within six months after that PSAP requests it, with TTY transcoding used until then.

    Transition From TTY to Real-Time Text Technology (final rule, FCC 16-169) · Summary of Report and Order — RTT and 911 · Checked 2026-10-02
24. 24
    RFC 4103 recommends a 300 ms buffering time when conditions are not known to require another value.

    RFC 4103: RTP Payload for Text Conversation · Section 5.1 · Checked 2026-10-02
25. 25
    RFC 4103's cps parameter sets the maximum characters per second a receiver accepts, defaulting to 30 averaged over any 10-second interval.

    RFC 4103: RTP Payload for Text Conversation · Section 6 · Checked 2026-10-02
26. 26
    47 CFR 67.3 incorporates IETF RFC 4103 (2005) by reference as the RTT standard for Part 67.

    47 CFR Part 67 — Real-Time Text · § 67.3 · Checked 2026-10-02
27. 27
    RFC 4103 recommends sending the original text plus two redundant generations unless conditions call for a different redundancy level.

    RFC 4103: RTP Payload for Text Conversation · Section 4 · Checked 2026-10-02
28. 28
    RFC 4103 is a Standards Track RFC that obsoletes RFC 2793 and has been updated by RFC 9071.

    RFC 4103 information page · Status / Obsoletes / Updated by fields · Checked 2026-10-02
29. 29
    The FCC required RTT to remain backward compatible with TTY technology during the transition, citing TTY users without IP access and PSAPs still using TTYs.

    Transition From TTY to Real-Time Text Technology (final rule, FCC 16-169) · Summary of Report and Order — RTT-TTY interoperability / backward compatibility · Checked 2026-10-02
30. 30
    47 CFR 67.1(g) defines real-time text (RTT) as text communications transmitted over Internet Protocol networks immediately as they are created.

    47 CFR Part 67 — Real-Time Text · § 67.1(g) · Checked 2026-10-02
31. 31
    47 CFR 9.10(c) excuses RTT support to the extent it is not achievable for a particular manufacturer to support RTT on the provider's network.

    47 CFR part 9 — 911 Requirements · § 9.10(c), second sentence, closing clause · Checked 2026-10-02
32. 32
    47 CFR 67.2(a) requires a covered service or device that supports RTT to interoperate with other RTT-supporting services and devices, either by conforming to RFC 4103 or by reliably transcoding to and from RFC 4103 or a mutually agreed internetworking protocol.

    47 CFR Part 67 — Real-Time Text · § 67.2(a), (a)(1), (a)(2) · Checked 2026-10-02
33. 33
    47 CFR 67.2(c)(2) requires covered RTT services to be able to transmit and receive RTT to and from any 911 public safety answering point (PSAP) in the United States.

    47 CFR Part 67 — Real-Time Text · § 67.2(c)(2) · Checked 2026-10-02
34. 34
    47 CFR 67.2(b) requires covered RTT services to be interoperable with TTYs, through an RFC 4103-TTY gateway or a mutually agreed transcoding protocol.

    47 CFR Part 67 — Real-Time Text · § 67.2(b) · Checked 2026-10-02
35. 35
    In the revised Section 508 standards, provision 412.5 Real-Time Text Functionality is reserved and contains no requirement.

    Revised 508 Standards and 255 Guidelines · 412.5 · Checked 2026-10-02
36. 36
    Section 508 provision 412.8.4 requires voice mail, auto-attendant, IVR and caller identification systems, where provided, to be usable with a TTY.

    Revised 508 Standards and 255 Guidelines · 412.8.4 · Checked 2026-10-02
37. 37
    Because 412.5 is reserved while 412.8 is in force, the current Section 508 standards impose TTY-compatibility requirements on two-way voice ICT but no RTT functional requirement.inferred

    Revised 508 Standards and 255 Guidelines · 412.5 read with 412.8 · Checked 2026-10-02
38. 38
    Section 508 provision 412.8.1 requires two-way voice ICT without built-in TTY functionality to include a standard non-acoustic connection point for TTYs.

    Revised 508 Standards and 255 Guidelines · 412.8, 412.8.1 · Checked 2026-10-02
39. 39
    Section 508 provision 412.8.3 requires ICT that interoperates with the PSTN to support all commonly used cross-manufacturer non-proprietary standard TTY signal protocols.

    Revised 508 Standards and 255 Guidelines · 412.8.3 · Checked 2026-10-02
40. 40
    47 CFR 67.2(c)(1) requires covered RTT services to initiate and receive RTT calls to and from the same telephone numbers used for voice calls.

    47 CFR Part 67 — Real-Time Text · § 67.2(c)(1) · Checked 2026-10-02
41. 41
    As of the 2026-09-01 eCFR, 47 CFR 20.18 is marked [Reserved] and carries no TTY or 911 text.

    47 CFR 20.18 [Reserved] · § 20.18 heading · Checked 2026-10-02
42. 42
    47 CFR 67.2(c)(3) requires covered RTT services to let users send and receive text and voice simultaneously in both directions on the same call using a single device.

    47 CFR Part 67 — Real-Time Text · § 67.2(c)(3) · Checked 2026-10-02
43. 43
    Teams Rooms participants can see but cannot send RTT, and Teams phone devices support RTT only in read-only mode.

    Manage real-time text (RTT) in Teams for users in your organization · User experience; Feature support > Supported · Checked 2026-10-02
44. 44
    Microsoft Teams supports RTT in meetings, group calls and 1:1 VoIP calls, including Teams Rooms meetings on Windows and Android, iOS and Android mobile, and compliance recordings.

    Manage real-time text (RTT) in Teams for users in your organization · Feature support > Supported · Checked 2026-10-02
45. 45
    Admins control Teams RTT for 1:1 VoIP calls with the RealTimeText parameter of Set-CsTeamsCallingPolicy, or with the Real-time-text (RTT) toggle under Voice > Calling policies in the Teams admin center.

    Manage real-time text (RTT) in Teams for users in your organization · Teams admin center for 1:1 VoIP calls; PowerShell for 1:1 VoIP calls · Checked 2026-10-02
46. 46
    The Teams RTT policy settings for meetings and group calls and for 1:1 VoIP calls are on by default.

    Manage real-time text (RTT) in Teams for users in your organization · Manage whether your users can use RTT in Teams meetings and group calls; Manage whether your users can use RTT in Teams 1:1 VoIP calls · Checked 2026-10-02
47. 47
    Teams RTT messages are included in the meeting transcript when the meeting is being transcribed.

    Use Real-time text (RTT) in Microsoft Teams · Transcripts note · Checked 2026-10-02
48. 48
    Admins control Teams RTT for meetings and group calls with the RealTimeText parameter of Set-CsTeamsMeetingPolicy, or with the Real-time-text (RTT) toggle under Meeting policies > Recording and transcription in the Teams admin center.

    Manage real-time text (RTT) in Teams for users in your organization · Teams admin center for meetings and group calls; PowerShell · Checked 2026-10-02
49. 49
    Microsoft Teams RTT is not supported for emergency calling.

    Manage real-time text (RTT) in Teams for users in your organization · Feature support > Not supported · Checked 2026-10-02
50. 50
    Microsoft Teams RTT is not supported on PSTN calls.

    Manage real-time text (RTT) in Teams for users in your organization · Feature support > Not supported · Checked 2026-10-02
51. 51
    Because Teams RTT excludes PSTN and emergency calls, a deaf or speech-disabled Teams Phone user cannot reach a PSAP by RTT from Teams and needs another route such as a mobile RTT, TTY or text-to-911 path.inferred

    Manage real-time text (RTT) in Teams for users in your organization · Feature support > Not supported · Checked 2026-10-02
52. 52
    A Teams user turns RTT on from the in-call More actions menu (Language and speech > Turn on RTT for this call on desktop and web), and once on it is enabled for all participants for the rest of that meeting or call.

    Use Real-time text (RTT) in Microsoft Teams · Turn on RTT section · Checked 2026-10-02
53. 53
    By December 31, 2019, Tier I CMRS providers opting for RTT had to support RTT on all new authorized end user devices.

    Transition From TTY to Real-Time Text Technology (final rule, FCC 16-169) · Summary of Report and Order — implementation timelines (Tier I) · Checked 2026-10-02
54. 54
    Tier I CMRS providers opting for RTT had to support it by December 31, 2017, either through a downloadable application or plug-in, or natively on at least one handset with updated design specifications.

    Transition From TTY to Real-Time Text Technology (final rule, FCC 16-169) · Summary of Report and Order — implementation timelines (Tier I) · Checked 2026-10-02
55. 55
    As of 2026-10-02 the TTY Relay elimination (FCC 25-79) and IP Relay RTT compatibility (FCC 26-4) measures are proposals; this pass found no final rules adopting them.inferred

    Internet-Based Telecommunications Relay Service Modernization (proposed rule, FCC 26-4) · Action: Proposed rule; DATES · Checked 2026-10-02
56. 56
    47 CFR 67.1(f) defines an RFC 4103-TTY gateway as a gateway that reliably and accurately transcodes between RFC 4103-conforming services and devices and circuit-switched networks that carry TTY communications.

    47 CFR Part 67 — Real-Time Text · § 67.1(f) · Checked 2026-10-02
57. 57
    Under the 2017 rules, covered entities that support RTT in compliance with the FCC's rules are relieved of their TTY support requirements.

    Transition From TTY to Real-Time Text Technology (final rule, FCC 16-169) · SUMMARY / Summary of Report and Order — TTY support relief · Checked 2026-10-02
58. 58
    Cisco Unity Connection requires G.711 mu-law as the message recording and storage codec for TTY, because its TTY prompt set is not compatible with G.729a or other codecs.

    System Administration Guide for Cisco Unity Connection Release 14 — Accessibility · TTY overview / Setting up TTY · Checked 2026-10-02
59. 59
    Cisco Unity Connection's TTY is a TUI language only with no text-to-speech; Cisco advises a dedicated TTY dial-in number, a TTY user template and a TTY class of service with text-to-speech disabled, and TTY cannot be used in interview handlers.

    System Administration Guide for Cisco Unity Connection Release 14 — Accessibility · TTY overview; Setting up TTY · Checked 2026-10-02
60. 60
    The 2017 RTT rules apply only to IP-based wireless services; the FCC said it was premature to address RTT in the wireline environment and kept the docket open.

    Transition From TTY to Real-Time Text Technology (final rule, FCC 16-169) · Summary of Report and Order — wireline / interconnected VoIP · Checked 2026-10-02

Documents

Cite this page

WarmTransfer. (2026, October 2). Real-time text and TTY accessibility requirements. WarmTransfer. https://warmtransfer.net/knowledge/rtt-tty-accessibility

@misc{warmtransfer-rtt-tty-accessibility,
  title  = {Real-time text and TTY accessibility requirements},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/rtt-tty-accessibility},
  note   = {Verified 2026-10-02}
}