Provisioning 911 addresses on SIP trunk numbers

See also

Sources

1. 1
   A Bandwidth DLR endpoint is defined by Alternate End User Identifier (AEUI) attributes: PIDF-LO enabled set true, a unique identifier of 10 to 30 characters, a callback number and a caller name, with preferred language optional.

   Dynamic Location Routing · section on endpoints / AEUI attributes · Checked 2026-10-14
2. 2
   Bandwidth requires TCP for DLR Location by Value and lat-lon-in-PIDF-LO calls, while Location by Reference can use UDP.

   E911 Dynamic Location Routing integration and testing guide · section on location methods / transport · Checked 2026-10-14
3. 3
   The callback number on a Bandwidth DLR endpoint must be a NANPA-valid number at which the 911 caller can be reached, and it is delivered to the PSAP.

   Dynamic Location Routing · section on endpoints / callback number · Checked 2026-10-14
4. 4
   By default Bandwidth ignores the Contact header on 911 calls; using it to carry caller name and callback number requires account configuration.

   E911 Dynamic Location Routing integration and testing guide · section on the Contact header · Checked 2026-10-14
5. 5
   Each PIDF-LO-enabled Bandwidth DLR endpoint needs a default location, used for taxation and as the location of record, which is not necessarily the location used to route the call; routing location is supplied in the SIP INVITE at call time.

   Dynamic Location Routing · section on endpoints / default location · Checked 2026-10-14
6. 6
   If a 911 call references a deleted Bandwidth AEUI or location identifier, Bandwidth cannot route it and sends it to its Emergency Call Center.

   Dynamic Location Routing · section on deleting endpoints or locations · Checked 2026-10-14
7. 7
   Bandwidth ignores the Geolocation-Routing header on DLR calls and advises setting it to no only when SIP intermediaries use the PIDF-LO for routing, otherwise omitting it.

   E911 Dynamic Location Routing integration and testing guide · section on 933 test call / Geolocation-Routing · Checked 2026-10-14
8. 8
   In Bandwidth 911 Dynamic Location Routing, each address is added to a location pool before use and gets a location ID unique across the account, up to 50 characters from [A-Za-z0-9], customer-supplied or Bandwidth-assigned.

   Dynamic Location Routing · section on locations / location IDs · Checked 2026-10-14
9. 9
   Bandwidth has no interop environment for DLR test calls; the interop API is for provisioning tests only, and call flows are validated with 933 calls in production.

   E911 Dynamic Location Routing integration and testing guide · section on interop and production environments · Checked 2026-10-14
10. 10
    Bandwidth routes a DLR 911 call whose identifier or address has no exact match to a provisioned record to the emergency call center as an unprovisioned call.

    E911 Dynamic Location Routing integration and testing guide · section on 911 test calls / unprovisioned calls · Checked 2026-10-14
11. 11
    For Bandwidth DLR calls the endpoint identifier goes in the From or P-Asserted-Identity header; if both are sent PAI is used, and Bandwidth recommends sending only From.

    E911 Dynamic Location Routing integration and testing guide · section on SIP INVITE headers · Checked 2026-10-14
12. 12
    Interconnected VoIP providers must advise every new and existing subscriber in plain language of situations in which E911 may be unavailable or limited, with relocation of equipment and use of a non-native number among the listed examples.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(5)(i) · Checked 2026-10-14
13. 13
    The current 47 CFR 9.11(b) requirements apply on or after January 6, 2021 for fixed interconnected VoIP services and on or after January 6, 2022 for non-fixed services.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b) introductory text · Checked 2026-10-14
14. 14
    A provider relying on Registered Location must identify when a 911 call comes from somewhere other than the Registered Location and then either prompt for a new location or update it automatically.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(4)(ii)(B)(3) · Checked 2026-10-14
15. 15
    Providers of fixed interconnected VoIP service must provide automated dispatchable location with each 911 call.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(4)(i) · Checked 2026-10-14
16. 16
    47 CFR 9.11 permits a provider that cannot obtain or confirm the caller's location to route the 911 call first to a national emergency call center to determine it.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(2)(iii) · Checked 2026-10-14
17. 17
    For non-fixed interconnected VoIP, a provider must give automated dispatchable location if technically feasible; otherwise it must provide Registered Location information or Alternative Location Information, or route the caller to a national emergency call center.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(4)(ii)(A)-(D) · Checked 2026-10-14
18. 18
    If a PSAP cannot receive or process ANI or location information, the VoIP provider need not supply it, but must still transmit all 911 calls over the Wireline E911 Network.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(3) · Checked 2026-10-14
19. 19
    A non-fixed interconnected VoIP provider relying on Registered Location must obtain each customer's Registered Location before service is initiated.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(4)(ii)(B)(1) · Checked 2026-10-14
20. 20
    A provider relying on Registered Location must offer customers one or more ways to update it at will and in a timely way, including at least one that needs only the CPE used to access the service.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(4)(ii)(B)(2) · Checked 2026-10-14
21. 21
    Under 47 CFR 9.11, all interconnected VoIP 911 calls must be routed using ANI and, if necessary, pseudo-ANI over the Wireline E911 Network.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(2)(iii) · Checked 2026-10-14
22. 22
    The interconnected VoIP E911 requirements in 47 CFR 9.11(b) apply to all interconnected VoIP providers, but only for 911 calls from users whose dispatchable location is in an area served by a Wireline E911 Network.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(1) · Checked 2026-10-14
23. 23
    Interconnected VoIP providers must transmit all 911 calls, together with ANI and the required location information, to the appropriate PSAP, designated statewide default answering point or emergency authority.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(2)(ii) · Checked 2026-10-14
24. 24
    MLTS installers, managers and operators must configure the system so a user can dial 911 directly, without a prefix, from any station equipped with dialing facilities.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.16(b)(1) · Checked 2026-10-14
25. 25
    An MLTS must provide automated dispatchable location for fixed on-premises telephones no later than January 6, 2021.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.16(b)(3)(i) · Checked 2026-10-14
26. 26
    MLTS notification of a 911 call must be initiated contemporaneously with the call, must not delay it, and must go to a location where someone is likely to see or hear it.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.16(b)(2) · Checked 2026-10-14
27. 27
    For off-premises MLTS devices, the system must provide automatic dispatchable location if technically feasible, and otherwise dispatchable location from end-user manual update or enhanced location information, which may be coordinate-based.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.16(b)(3)(iii) · Checked 2026-10-14
28. 28
    47 CFR 9.3 defines dispatchable location as a location delivered to the PSAP with a 911 call that consists of the validated street address of the calling party, together with further detail set out in the rest of the definition.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.3, definition of Dispatchable location · Checked 2026-10-14
29. 29
    47 CFR 9.3 defines pseudo-ANI as a number with the same number of digits as ANI that is not a NANP telephone number and may be used in place of ANI to convey special meaning.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.3, definition of Pseudo-Automatic Number Identification (Pseudo-ANI) · Checked 2026-10-14
30. 30
    47 CFR 9.3 defines Registered Location as the most recent location information obtained by an interconnected VoIP or TRS provider that identifies the user's physical location.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.3, definition of Registered Location · Checked 2026-10-14
31. 31
    Because static carrier 911 records are keyed to the presented number, a PBX that presents a number registered at a different site will likely deliver that site's address and PSAP rather than the caller's.inferred

    Emergency Calling for SIP Trunking · sections on registering an emergency address and From header requirements · Checked 2026-10-14
32. 32
    Across Twilio, Telnyx, Bandwidth and IntelePeer, an emergency call whose presented identity does not match a provisioned 911 record is not routed on a registered address; the documented outcomes are diversion to a national emergency call center, often with a charge.inferred

    Emergency Calling for SIP Trunking · section on emergency calls from numbers without a registered address; synthesis with the cited Telnyx, Bandwidth and IntelePeer claims · Checked 2026-10-14
33. 33
    IntelePeer requires customer equipment that can send and is correctly configured to send Dynamic 911 SIP headers in the INVITE, and refers customers to their equipment vendor for specific headers.

    IntelePeer Dynamic 911 Configuration Guide · prerequisites section · Checked 2026-10-14
34. 34
    IntelePeer states that if no Dynamic 911 locations are configured, all 911 calls are routed to the National Emergency Call Center.

    IntelePeer Dynamic 911 Configuration Guide · section on Locations · Checked 2026-10-14
35. 35
    In the IntelePeer Customer Portal, numbers get 911 service as Static 911, Generic Dynamic 911 or Microsoft Teams Dynamic 911, and Static 911 applies one dispatch address to all selected numbers.

    IntelePeer Dynamic 911 Configuration Guide · section on adding E911 to numbers · Checked 2026-10-14
36. 36
    IntelePeer requires a validated taxation address on each Dynamic 911 number and states it is used for taxation only, not to route subsequent 911 calls.

    IntelePeer Dynamic 911 Configuration Guide · section on Dynamic 911 number settings · Checked 2026-10-14
37. 37
    RFC 6442 conveys location in SIP either by value, as a PIDF-LO MIME body referenced by a cid: URI in the Geolocation header, or by reference, as a location URI the recipient dereferences.

    RFC 6442: Location Conveyance for the Session Initiation Protocol · RFC 6442 sections 3.1, 3.2 and 4.1 · Checked 2026-10-14
38. 38
    Under RFC 6442 the Geolocation-Routing header takes yes or no, defaults to no, and intermediaries must not use conveyed location for routing unless it is yes.

    RFC 6442: Location Conveyance for the Session Initiation Protocol · RFC 6442 sections 4.1 and 4.2 · Checked 2026-10-14
39. 39
    Telnyx 933 testing is available for US and Canada E911 only; a successful 933 call confirms the address associated with the test call and does not dispatch emergency services.

    How do I test E911 service? · 933 test procedure paragraph · Checked 2026-10-14
40. 40
    For a Telnyx E911 call or 933 test, the caller ID presented to Telnyx must be the Telnyx number that has E911 enabled.

    How do I test E911 service? · caller ID requirements paragraph · Checked 2026-10-14
41. 41
    With Telnyx API-based Dynamic E911, the INVITE carries the provisioned sip_geolocation_id in the Geolocation header and the sip_from_id in the From or P-Asserted-Identity header.

    Emergency Calling: Dynamic E911 · section on SIP headers for API-based addresses · Checked 2026-10-14
42. 42
    Telnyx says an emergency call made before a dynamically provisioned endpoint is fully activated is routed to a national emergency call center.

    Emergency Calling: Dynamic E911 · section on just-in-time provisioning / activation timing · Checked 2026-10-14
43. 43
    Telnyx Dynamic E911 offers two methods: API pre-provisioned addresses for fixed locations, and real-time GPS coordinates sent as PIDF-LO in the SIP INVITE for mobile and IoT devices.

    Emergency Calling: Dynamic E911 · overview section listing the two methods · Checked 2026-10-14
44. 44
    Telnyx recommends pre-provisioning a persistent emergency address rather than relying only on just-in-time provisioning.

    Emergency Calling: Dynamic E911 · section on just-in-time provisioning / activation timing · Checked 2026-10-14
45. 45
    Telnyx says the E911-enabled number should be presented in +E.164 format with the leading plus and country code, and that without it Telnyx may fail to match the call to the registered address.

    How do I test E911 service? · caller ID requirements paragraph · Checked 2026-10-14
46. 46
    In the Telnyx Mission Control Portal, E911 is enabled per number: open the number's emergency settings, turn on emergency services, select or add an address with suite or floor detail, accept the monthly charge, and confirm the number shows ready or active.

    E911 Setup Guide · numbered setup steps 1-6 · Checked 2026-10-14
47. 47
    Telnyx states that emergency calls from numbers with no registered address or no enabled emergency service are treated as unregistered and incur a $100 penalty.

    How do I test E911 service? · warning paragraph on unregistered calls · Checked 2026-10-14
48. 48
    Twilio notes that 933 may need to be added to the PBX dial plan, and that a 933 test call uses the Request-URI sip:933@{trunk}.pstn.twilio.com.

    Emergency Calling for SIP Trunking · section on testing (933) · Checked 2026-10-14
49. 49
    On Twilio Elastic SIP Trunking in the US and Canada, dialling 933 reaches an automated system that reads back the calling Twilio number and its associated emergency address without reaching a PSAP.

    Emergency Calling for SIP Trunking · section on testing (933) · Checked 2026-10-14
50. 50
    To change a number's emergency address on Twilio Elastic SIP Trunking, disassociate the current address, confirm the number shows unregistered, then associate the new address and confirm it shows registered.

    Emergency Calling for SIP Trunking · section on changing or modifying an emergency address · Checked 2026-10-14
51. 51
    On Twilio Elastic SIP Trunking, an emergency address is added from the trunk's Numbers tab or a number's configuration page, and one address may be used for any phone number associated with the account's trunks.

    Emergency Calling for SIP Trunking · section on registering an emergency address · Checked 2026-10-14
52. 52
    Twilio Elastic SIP Trunking requires every emergency call to carry a valid From header containing an E.164-formatted SIP URI.

    Emergency Calling for SIP Trunking · section on making emergency calls / From header requirements · Checked 2026-10-14
53. 53
    On Twilio Elastic SIP Trunking, the From number of an emergency call must be a Twilio number enabled for emergency calling and associated with the trunk carrying the call.

    Emergency Calling for SIP Trunking · section on making emergency calls / From header requirements · Checked 2026-10-14
54. 54
    Twilio requires the dialled emergency number to be valid for the same country as the From number on an Elastic SIP Trunking emergency call.

    Emergency Calling for SIP Trunking · section on making emergency calls / From header requirements · Checked 2026-10-14
55. 55
    For US and Canada numbers on Twilio Elastic SIP Trunking, the emergency address must be recognised by the Master Street Address Guide (MSAG) database.

    Emergency Calling for SIP Trunking · section on address validation (MSAG) · Checked 2026-10-14
56. 56
    Twilio notes that the MSAG form of an address often differs from the USPS form because it uses the community name (township, city or county) served by the responding PSAP.

    Emergency Calling for SIP Trunking · section on address validation (MSAG) · Checked 2026-10-14
57. 57
    Twilio states that associating a validated emergency address with a number avoids the per-call unregistered fee but incurs a monthly fee.

    Emergency Calling for SIP Trunking · section on emergency calls from numbers without a registered address · Checked 2026-10-14
58. 58
    Twilio Elastic SIP Trunking routes emergency calls to PSAPs in the US, Canada, UK, Australia, Ireland, France, Germany and Austria, with both E911 and Basic 911 supported in the US and Canada.

    Emergency Calling for SIP Trunking · opening section on supported countries · Checked 2026-10-14
59. 59
    In the US and Canada, a 911 call over Twilio Elastic SIP Trunking from a number with no registered emergency address incurs a per-call emergency calling fee and is sent to a national emergency call center rather than straight to the local PSAP.

    Emergency Calling for SIP Trunking · section on emergency calls from numbers without a registered address · Checked 2026-10-14

Documents

Cite this page

WarmTransfer. (2026, October 14). Provisioning 911 addresses on SIP trunk numbers. WarmTransfer. https://warmtransfer.net/knowledge/sip-trunk-e911-provisioning

@misc{warmtransfer-sip-trunk-e911-provisioning,
  title  = {Provisioning 911 addresses on SIP trunk numbers},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/sip-trunk-e911-provisioning},
  note   = {Verified 2026-10-14}
}