Dynamic E911

Microsoft Teams integrations only: Before using PIDF-LO or geolocation coordinates for 911 calling with Microsoft Teams, open a support ticket with Telnyx Support. Include each phone number and its corresponding SIP connection ID. Wait for Telnyx Support to confirm activation before using these methods for Teams 911 calls.

Dynamic E911 delivers location information to PSAPs during emergency calls. Two methods available:

Method	Use case	Location source
API-based addresses	Fixed locations (offices, buildings)	Pre-provisioned via API
GPS coordinates	Mobile devices, wearables, IoT	PIDF-LO in SIP INVITE

API-based addresses

Pre-provision addresses and endpoints, then reference IDs in SIP headers during calls.

Dynamically provisioning emergency endpoints may result in a delay before the associated address is fully available for routing. Telnyx recommends pre-provisioning a persistent emergency address rather than relying on just-in-time provisioning. In circumstances where an emergency call (e.g., 911) is initiated before a dynamically provisioned endpoint is fully activated, the call will be routed to a national emergency call center (PSAP) .

Create emergency address

POST /v2/dynamic_emergency_addresses

{
  "house_number": "1901",
  "street_pre_directional": "W",
  "street_name": "MADISON",
  "street_suffix": "ST",
  "locality": "CHICAGO",
  "administrative_area": "IL",
  "postal_code": "60612",
  "country_code": "US"
}

Response includes:

id - Address UUID for endpoint association
sip_geolocation_id - Include in Geolocation header
status - pending during validation, activated when ready

Create emergency endpoint

POST /v2/dynamic_emergency_endpoints

{
  "dynamic_emergency_address_id": "uuid-from-address",
  "callback_number": "+13125550000",
  "caller_name": "Jane Doe"
}

Response includes:

sip_from_id - Include in From or P-Asserted-Identity header

SIP INVITE format

Include both IDs in emergency call INVITE:

INVITE sip:[email protected] SIP/2.0
From: <sip:{sip_from_id}@origin.example.com>
To: <sip:[email protected]>
Geolocation: {sip_geolocation_id}

Alternative using P-Asserted-Identity:

P-Asserted-Identity: <sip:{sip_from_id}@origin.example.com>
Geolocation: {sip_geolocation_id}

GPS coordinates (PIDF-LO)

Pass real-time coordinates in PIDF-LO format for mobile devices, wearables, and IoT.

Coordinate format

Parameter	Range	Notes
Latitude	-90 to +90	Negative = South
Longitude	-180 to +180	Negative = West
Precision	6-8 decimal places	Meter-level accuracy

SIP INVITE Format for PIDF-LO with GPS Coordinates

INVITE sip:[email protected] SIP/2.0
From: <sip:[email protected]>
To: <sip:[email protected]>
Geolocation: <cid:[email protected]>
X-Latitude: latitude
X-Longitude: longitude
Content-Type: application/sdp
[SDP content]

SIP INVITE Format for PIDF-LO with MIME

The identity, civic address, and coordinates below are illustrative example values. Replace them with the caller’s identity and actual location.

INVITE sip:[email protected] SIP/2.0
From: <sip:[email protected]>
To: <sip:[email protected]>
Geolocation: <cid:[email protected]>
Content-Type: multipart/mixed;boundary=boundary1

--boundary1
Content-Type: application/sdp

[SDP content]

--boundary1
Content-Type: application/pidf+xml
Content-ID: <[email protected]>

<?xml version="1.0" encoding="utf-8"?>
<presence xmlns:xsd="http://www.w3.org/2001/XMLSchema"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          entity="sip:[email protected]"
          xmlns="urn:ietf:params:xml:ns:pidf">
  <tuple id="tuple0">
    <status>
      <geopriv xmlns="urn:ietf:params:xml:ns:pidf:geopriv10">
        <location-info>
          <Point srsName="urn:ogc:def:crs:EPSG::4326" xmlns="http://www.opengis.net/gml">
            <pos>41.881000 -87.674000</pos>
          </Point>
          <civicAddress xmlns="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr">
            <country>US</country>
            <A1>IL</A1>
            <A3>CHICAGO</A3>
            <PRD>W</PRD>
            <RD>MADISON</RD>
            <STS>ST</STS>
            <HNO>1901</HNO>
            <NAM>Acme Corp</NAM>
            <PC>60612</PC>
          </civicAddress>
        </location-info>
        <usage-rules>
          <retransmission-allowed xmlns="urn:ietf:params:xml:ns:pidf:geopriv10:basicPolicy">true</retransmission-allowed>
        </usage-rules>
        <method>LIS</method>
      </geopriv>
    </status>
    <timestamp>2026-10-13T10:30:00Z</timestamp>
  </tuple>
</presence>

--boundary1--

Telnyx currently supports LIS and ASSIST as PIDF-LO methods.
Other methods are not supported.

PIDF-LO requirements

Element	Requirement
`<pos>` (GML namespace)	Latitude then longitude, space-separated
`srsName`	Must be `urn:ogc:def:crs:EPSG::4326`
`<timestamp>`	ISO 8601 format; child of `<tuple>` in the PIDF namespace

Testing

Use test number 933 to simulate emergency calls without dispatching services.

Address field limits

Field	Required	Max Length	PIDF-LO Element
house_number	No	16	HNO
house_suffix	No	45	HNS
street_pre_directional	No	2	PRD
street_name	Yes	200	RD
street_suffix	No	45	STS
street_post_directional	No	2	POD
extended_address	No	60*	LOC
locality	Yes	100	A3
administrative_area	Yes	2	A1
postal_code	Yes	10	PC
country_code	Yes	2	country
caller_name	No	50	-

*Common terms auto-abbreviated: APARTMENT→APT, FLOOR→FL, SUITE→STE, BUILDING→BLDG, ROOM→RM

Getting Started

Authentication

Configuration

Routing

Network Configuration

Features

STIR/SHAKEN

Emergency Calling

Troubleshooting

SIP Integrations Guides

API Reference

For AI Agents

API-based addresses

Create emergency address

Create emergency endpoint

SIP INVITE format

GPS coordinates (PIDF-LO)

Coordinate format

SIP INVITE Format for PIDF-LO with GPS Coordinates

SIP INVITE Format for PIDF-LO with MIME

PIDF-LO requirements

Testing

Address field limits

​API-based addresses

​Create emergency address

​Create emergency endpoint

​SIP INVITE format

​GPS coordinates (PIDF-LO)

​Coordinate format

​SIP INVITE Format for PIDF-LO with GPS Coordinates

​SIP INVITE Format for PIDF-LO with MIME

​PIDF-LO requirements

​Testing

​Address field limits

API-based addresses

Create emergency address

Create emergency endpoint

SIP INVITE format

GPS coordinates (PIDF-LO)

Coordinate format

SIP INVITE Format for PIDF-LO with GPS Coordinates

SIP INVITE Format for PIDF-LO with MIME

PIDF-LO requirements

Testing

Address field limits