ALI databases and MSAG address validation

See also

Sources

1. 1
   Bandwidth's 911 FAQ body and its glossary section expand VPC as 'VoIP Provisioning Center', which conflicts with NENA's definition of VPC as 'VoIP Positioning Center' (the FAQ's own page description also uses Positioning).disputed

   911 FAQ · 911 FAQ, 'What is a VoIP Provisioning Center, and does yours meet regulatory requirements?' · Checked 2026-10-14
2. 2
   Bandwidth reports an average 98 percent success rate for 911 address validation on initial submission, with its engine suggesting alternative matches at submission time.

   911 FAQ · 911 FAQ, 'What is the average error rate?' · Checked 2026-10-14
3. 3
   Bandwidth says it updates its geocode and MSAG databases daily using Baseline and Delta files from the MSAG Operator plus local authority data.

   Master Street Address Guide (MSAG) · Master Street Address Guide (MSAG) glossary entry, data maintenance · Checked 2026-10-14
4. 4
   Bandwidth validates a submitted civic or postal 911 address by geocoding it to assign an X/Y coordinate, which it treats as confirming successful validation.

   Master Street Address Guide (MSAG) · Master Street Address Guide (MSAG) glossary entry, validation process · Checked 2026-10-14
5. 5
   After geocoding, Bandwidth stores each validated address in the MSAG-compliant format for the relevant jurisdiction so it can answer PSAP queries for that telephone number.

   Master Street Address Guide (MSAG) · Master Street Address Guide (MSAG) glossary entry, validation process · Checked 2026-10-14
6. 6
   Bandwidth's glossary states that state and municipal authorities are responsible for updating the MSAG and making it available, with an MSAG Coordinator or Administrator maintaining it for PSAP use.

   Master Street Address Guide (MSAG) · Master Street Address Guide (MSAG) glossary page, MSAG Operator and MSAG Coordinator entries · Checked 2026-10-14
7. 7
   Bandwidth's glossary describes an MSAG address as absolute and unique, disallowing variants in directionals, street spelling, suffixes and community names.

   Master Street Address Guide (MSAG) · Master Street Address Guide (MSAG) glossary page, MSAG Address entry · Checked 2026-10-14
8. 8
   Bandwidth's 911 FAQ says the carrier of record has 48 hours to respond to an NRF, after which Bandwidth releases the record to the customer to validate.

   911 FAQ · 911 FAQ, 'What happens when a No Records Found alert is triggered?' · Checked 2026-10-14
9. 9
   Bandwidth sends a No Records Found (NRF) alert when no matching record is found for a submitted 911 record, for example when address numbers are transposed, and notifies both the customer and the other carrier involved.

   911 FAQ · 911 FAQ, 'What happens when a No Records Found alert is triggered?' · Checked 2026-10-14
10. 10
    47 CFR 9.3 defines Automatic Location Information (ALI) as information transmitted while providing E911 service that permits emergency service providers to identify the geographic location of the calling party.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.3, definition 'Automatic Location Information (ALI)' · Checked 2026-10-14
11. 11
    47 CFR 9.3 defines alternative location information as location information, which may be coordinate-based, sufficient to identify the caller's civic address and approximate in-building location, including floor level in large buildings.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.3, definition 'Alternative location information' · Checked 2026-10-14
12. 12
    47 CFR 9.3 defines dispatchable location as a location delivered to the PSAP with a 911 call consisting of the validated street address of the calling party plus additional information such as suite or apartment needed to adequately identify the caller's location (CMRS providers excepted).

    47 CFR part 9 — 911 Requirements · 47 CFR 9.3, definition 'Dispatchable location' · Checked 2026-10-14
13. 13
    47 CFR 9.3 defines pseudo-ANI as a number with the same digit count as ANI that is not a NANP directory number, used in place of ANI to convey a special meaning set by agreement among the originating, intermediate and destination systems.

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

    47 CFR part 9 — 911 Requirements · 47 CFR 9.3, definition 'Registered Location' · Checked 2026-10-14
15. 15
    The 47 CFR 9.3 dispatchable location definition requires a validated street address but does not specify MSAG, GIS or any particular validation authority, so the validation method is set by the 911 system and its providers, not by that definition.inferred

    47 CFR part 9 — 911 Requirements · 47 CFR 9.3, definition 'Dispatchable location' (absence of any named validation database) · Checked 2026-10-14
16. 16
    47 CFR 9.3 defines the Wireline E911 Network as a dedicated wireline network, interconnected with but largely separate from the PSTN, that includes a selective router and routes emergency calls and related information to PSAPs and other emergency answering points.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.3, definition 'Wireline E911 Network' · Checked 2026-10-14
17. 17
    In Maine, when an address fails MSAG validation the carrier should first contact the designated municipal Addressing Officer, and MSAG problems go to the ESCB GIS office.

    Database Maintenance (Maine 9-1-1, Phone Service Providers) · Database Maintenance page, MSAG and Addressing Officer guidance · Checked 2026-10-14
18. 18
    In Maine, the 9-1-1 database is maintained by the carriers, which are asked to validate addresses against the MSAG during service orders.

    Database Maintenance (Maine 9-1-1, Phone Service Providers) · Database Maintenance page, carrier responsibilities · Checked 2026-10-14
19. 19
    In Maine, ALI discrepancies reported by PSAPs are sent to carriers daily through Maine LDB Manager and should be researched and corrected within 3 business days.

    Database Maintenance (Maine 9-1-1, Phone Service Providers) · Database Maintenance page, ALI discrepancies · Checked 2026-10-14
20. 20
    Maine makes daily MSAG delta files and a full weekly MSAG available through LDB Manager to users with permissions.

    Database Maintenance (Maine 9-1-1, Phone Service Providers) · Database Maintenance page, MSAG files · Checked 2026-10-14
21. 21
    47 CFR 9.16(b)(3)(i) requires on-premises fixed telephones associated with an MLTS to provide automated dispatchable location no later than January 6, 2021.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.16(b)(3)(i) · Checked 2026-10-14
22. 22
    47 CFR 9.16(b)(3)(ii) requires on-premises non-fixed MLTS devices, no later than January 6, 2022, to provide automated dispatchable location when technically feasible, otherwise dispatchable location from end-user manual update or alternative location information.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.16(b)(3)(ii) · Checked 2026-10-14
23. 23
    47 CFR 9.16(b)(3)(iii) requires off-premises MLTS devices, no later than January 6, 2022, to provide automatic dispatchable location if technically feasible, 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
24. 24
    NENA defines ALI as the automatic display at the PSAP of the caller's telephone number, the address or location of the telephone, and supplementary emergency services information about the location the call came from.

    ALI (Automatic Location Identification) · ALI (Automatic Location Identification), definition · Checked 2026-10-14
25. 25
    NENA describes ALI Retrieval as the process in which a PSAP sends an ALI Request to the ALI database and receives back the location and other available information.

    ALI (Automatic Location Identification) · ALI (Automatic Location Identification), Related Terms: ALI Request, ALI Retrieval · Checked 2026-10-14
26. 26
    NENA describes the Customer Name Field as the part of the traditional ALI format that shows the customer name or other pre-filled identifying information to the 9-1-1 telecommunicator.

    ALI (Automatic Location Identification) · ALI (Automatic Location Identification), Related Terms: Customer Name Field · Checked 2026-10-14
27. 27
    NENA defines the ECRF as an NG9-1-1 Core Services functional element acting as a LoST server that takes a civic or geodetic location plus a Service URN and returns a URI used to route the emergency call to the appropriate PSAP or responder agency.

    ECRF (Emergency Call Routing Function) · ECRF (Emergency Call Routing Function), definition · Checked 2026-10-14
28. 28
    NENA defines the ERDB as a database of routing information for each ESZ in a serving area, supporting ESZ boundary definitions and mapping civic address or geo-spatial coordinate location to a specific ESZ.

    ERDB (Emergency Routing Database) · ERDB (Emergency Routing Database), definition · Checked 2026-10-14
29. 29
    NENA defines an ESN as a 3-5 digit number that represents one or more ESZs, and distinguishes Administrative ESNs from Routing ESNs.

    ESN (Emergency Service Number) · ESN (Emergency Service Number), definition · Checked 2026-10-14
30. 30
    NENA defines an ESZ as a geographic area representing a unique combination of emergency service agencies (law enforcement, fire, EMS) within a 9-1-1 governing authority's jurisdiction, identifiable by an ESN.

    ESZ (Emergency Service Zone) · ESZ (Emergency Service Zone), definition · Checked 2026-10-14
31. 31
    NENA-STA-005 is the NENA standard for provisioning and maintaining GIS data to ECRFs and LVFs.

    LVF (Location Validation Function) · LVF (Location Validation Function), Relevant NENA Documents · Checked 2026-10-14
32. 32
    NENA defines the LVF (Location Validation Function) as an NG9-1-1 Core Services functional element that acts as a LoST server and validates civic location information against authoritative GIS database records.

    LVF (Location Validation Function) · LVF (Location Validation Function), definition · Checked 2026-10-14
33. 33
    NENA treats a civic address as valid in the LVF when it can be uniquely matched to authoritative GIS records, supports an accurate emergency call route, and is specific enough to guide responders to the location.

    LVF (Location Validation Function) · LVF (Location Validation Function), definition (validity criteria) · Checked 2026-10-14
34. 34
    NENA defines the MSAG as a database of street names and house number ranges within their associated communities, defining Emergency Service Zones (ESZs) and their Emergency Service Numbers (ESNs) so that 9-1-1 calls route properly.

    MSAG (Master Street Address Guide) · MSAG (Master Street Address Guide), definition · Checked 2026-10-14
35. 35
    NENA's MSAG glossary entry lists NENA 02-011 (data standards for LECs, ALI service providers and 9-1-1 jurisdictions), NENA 71-501 (synchronizing GIS with MSAG and ALI), NENA-STA-010 (i3) and NENA-STA-015 (data formats for 9-1-1 data exchange and GIS mapping) as the relevant documents.

    MSAG (Master Street Address Guide) · MSAG (Master Street Address Guide), Relevant NENA Documents · Checked 2026-10-14
36. 36
    NENA defines the VPC (VoIP Positioning Center) as the element that provides routing information for VoIP emergency calls and cooperates in delivering location information to the PSAP over the existing ALI database infrastructure.

    VPC (VoIP Positioning Center) · VPC (VoIP Positioning Center), definition · Checked 2026-10-14
37. 37
    In an NG9-1-1 i3 environment, the authoritative check on a civic address moves from tabular MSAG range matching to LVF validation against authoritative GIS data, while legacy E9-1-1 continues to depend on the MSAG.inferred

    LVF (Location Validation Function) · LVF (Location Validation Function), definition; read together with MSAG (Master Street Address Guide), definition · Checked 2026-10-14
38. 38
    An address that is deliverable by USPS can still fail MSAG validation, so postal validation alone is not evidence that a 911 address will provision correctly.inferred

    Emergency Calling for SIP Interfaces · Emergency Calling for SIP Interfaces, MSAG vs USPS note · Checked 2026-10-14
39. 39
    A validated Teams emergency address can be modified only in specific regions; elsewhere, a change in the address's format or representation requires creating a new address.

    Plan and manage emergency calling · Plan and manage emergency calling, 'Changing an emergency address' · Checked 2026-10-14
40. 40
    For Microsoft Calling Plans in the United States and Canada, an emergency location is required when a phone number is assigned to a user.

    Considerations for Calling Plans · Considerations for Calling Plans, 'Emergency call enablement for Calling Plans' · Checked 2026-10-14
41. 41
    For US Calling Plans, if a Teams client is not at a tenant-defined dynamic emergency location, a national call center screens the emergency call for location before transferring it, and if the caller cannot update their location the call goes to the PSAP serving the registered address.

    Considerations for Calling Plans · Considerations for Calling Plans, 'Emergency call routing for different countries/regions', United States row · Checked 2026-10-14
42. 42
    To assign a Teams emergency location to a network identifier for dynamic emergency calling, the emergency address must contain an appropriate geo code.

    Plan and manage emergency calling · Plan and manage emergency calling, 'Emergency address geo codes', Important note · Checked 2026-10-14
43. 43
    An emergency address created with the address map search feature in the Teams admin center is automatically marked validated and given a geo code.

    Plan and manage emergency calling · Plan and manage emergency calling, 'Emergency address validation' and 'Emergency address geo codes' · Checked 2026-10-14
44. 44
    Microsoft's Teams emergency calling planning page says validation ensures an address is legitimate but does not name the MSAG or disclose which database validation is checked against.

    Plan and manage emergency calling · Plan and manage emergency calling, 'Emergency address validation' (full page read; no MSAG mention) · Checked 2026-10-14
45. 45
    In Microsoft Teams, an emergency address must be marked validated before it can be assigned to a user or to a network identifier.

    Plan and manage emergency calling · Plan and manage emergency calling, 'Emergency address validation' · Checked 2026-10-14
46. 46
    Twilio states that emergency test dialing to 933 is available only in the US and Canada.

    Emergency Calling for SIP Interfaces · Emergency Calling for SIP Interfaces, supported regions / testing · Checked 2026-10-14
47. 47
    To move a Twilio number to a new emergency address, the administrator disassociates the current address, confirms the number's Emergency Address Status shows unregistered, associates the new address, and confirms it shows registered.

    Emergency Calling for SIP Interfaces · Emergency Calling for SIP Interfaces, changing an emergency address · Checked 2026-10-14
48. 48
    To edit an existing Twilio emergency address, it must first be disassociated from every number using it and show unregistered, then edited, re-associated, and confirmed registered.

    Emergency Calling for SIP Interfaces · Emergency Calling for SIP Interfaces, modifying an existing emergency address · Checked 2026-10-14
49. 49
    Twilio requires a US or Canadian emergency address for its SIP interfaces to be recognized by the MSAG database.

    Emergency Calling for SIP Interfaces · Emergency Calling for SIP Interfaces, address validation section · Checked 2026-10-14
50. 50
    Twilio states that a US MSAG address often differs from the USPS address for the same location because the MSAG uses the community name (township, city, county) served by the responding PSAP.

    Emergency Calling for SIP Interfaces · Emergency Calling for SIP Interfaces, address validation section (MSAG vs USPS note) · Checked 2026-10-14
51. 51
    In the Twilio Console, if an emergency address cannot be validated after Save & Continue, the administrator is asked to pick from suggested alternative addresses, and the selected address is then associated with the chosen numbers.

    Emergency Calling for SIP Interfaces · Emergency Calling for SIP Interfaces, address validation section · Checked 2026-10-14
52. 52
    Under 47 CFR 9.11(b)(2)(iv), the location information an interconnected VoIP provider delivers must be available to the appropriate PSAP from or through the appropriate ALI database.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(2)(iv) · Checked 2026-10-14
53. 53
    47 CFR 9.11(b)(2)(iii) requires interconnected VoIP 911 calls to be routed using ANI and, if necessary, pseudo-ANI over the dedicated Wireline E911 Network.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(2)(iii) · Checked 2026-10-14
54. 54
    The 47 CFR 9.11(b) interconnected VoIP E911 requirements apply on or after January 6, 2021 for fixed 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
55. 55
    47 CFR 9.11(b)(4)(i) requires providers of fixed interconnected VoIP services to 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
56. 56
    47 CFR 9.11(b)(4)(ii)(B)(3) requires the provider to identify whether the service is being used to call 911 from a location other than the Registered Location and then either prompt for a new Registered Location or update it without further customer action.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(4)(ii)(B)(3) · Checked 2026-10-14
57. 57
    47 CFR 9.11(b)(2)(iii) allows an interconnected VoIP provider to route a 911 call first to a national emergency call center when it cannot obtain or confirm the caller's location information.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(2)(iii), proviso · Checked 2026-10-14
58. 58
    Under the Registered Location option in 47 CFR 9.11(b)(4)(ii)(B)(1), a non-fixed interconnected VoIP provider must obtain the Registered Location from the customer before service begins.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(4)(ii)(B)(1) · Checked 2026-10-14
59. 59
    47 CFR 9.11(b)(4)(ii)(B)(2) requires the provider to give end users one or more methods of updating their Registered Location, at least one of which needs only the CPE required to access the service.

    47 CFR part 9 — 911 Requirements · 47 CFR 9.11(b)(4)(ii)(B)(2) · Checked 2026-10-14

Documents

Cite this page

WarmTransfer. (2026, October 14). ALI databases and MSAG address validation. WarmTransfer. https://warmtransfer.net/knowledge/ali-msag-location-provisioning

@misc{warmtransfer-ali-msag-location-provisioning,
  title  = {ALI databases and MSAG address validation},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/ali-msag-location-provisioning},
  note   = {Verified 2026-10-14}
}