Bring your own SIP trunk

If your business already has phone numbers with a carrier, you don’t have to move them. Talkif connects to your carrier’s SIP trunk: inbound calls to your numbers reach Talkif’s agents, and outbound calls go out through your carrier under your caller IDs. You keep your carrier contract, your rates for the PSTN leg, and your numbers; Talkif charges only its per-minute SIP rate for the AI leg.

There’s a second, simpler path if your numbers are in Twilio: connect your Twilio account directly, no trunk needed. Both are below.

How SIP trunking with Talkif works

Inbound: your carrier sends calls for your numbers to Talkif’s SIP address. Talkif answers with the flow connected to that number.
Outbound: Talkif sends the call to your carrier’s SIP host with the credentials you provide; the carrier terminates it to the PSTN.
Talkif does not register with your carrier. There’s no SIP REGISTER; traffic is authenticated by IP allowlist in both directions plus the trunk username/password for outbound.

That last point is the one that causes most setup failures, so:

Add Talkif's SIP address to your carrier's IP allowlist

Outbound calls from Talkif arrive at your carrier from sip.talkif.ai = 63.176.211.13, port 5060. Your carrier must accept SIP from that address, or every outbound call fails at INVITE. Inbound works the other way: Talkif only accepts SIP from the carrier IPs you list on the provider.

Before you start

Have these from your carrier:

Item	Example	Notes
SIP host	`sip.mycarrier.com`	The host Talkif sends outbound calls to
Port	`5060`	Default 5060; TLS trunks commonly use 5061
Protocol	`UDP`, `TCP` or `TLS`	Whatever the trunk is provisioned for
Trunk username and password		Used by Talkif to authenticate outbound INVITEs
Carrier source IPs or CIDR	`185.45.12.34` or `185.45.12.0/24`	The addresses your carrier sends inbound calls from. Required for inbound
Your numbers	`+15551234567`	E.164

And on the carrier side, ask them to (1) allowlist 63.176.211.13, and (2) route inbound calls for your numbers to sip.talkif.ai:5060.

Setting it up

Create the SIP provider

Phone Numbers → Providers → Add → SIP Provider. Enter the SIP host, port, protocol, username and password, and the carrier’s IP addresses or CIDR. Give it a name you’ll recognise. Providers are set up in the dashboard; the API can list them but not create them.

Point your carrier at Talkif

Have the carrier send inbound calls for your numbers to sip.talkif.ai on port 5060, and allow SIP from 63.176.211.13. Most carriers do this in a “trunk” or “DID routing” screen; some need a support ticket.

Register your numbers

Under the provider, add each number in E.164 form. SIP numbers are Active immediately — there’s no verification call.

Connect flows and test both directions

Connect a published flow to a number and dial it from a phone (inbound). Then use Start a call from that number to your phone (outbound). If one direction fails, the table below says where to look.

When it doesn’t work

Symptom	Almost always
Inbound: your number rings out or the carrier reports “unreachable”	The carrier isn’t routing to `sip.talkif.ai:5060`, or the carrier’s source IP isn’t in the provider’s IP list — check the carrier’s actual signalling IPs, which are often not the SIP host’s address
Inbound: answered busy, a failed call appears in History	Talkif got the call; no flow is connected to the number, or your balance is below the minimum. See How a call works
Outbound: fails immediately, `provider_error`	The carrier rejected the INVITE — `63.176.211.13` isn’t allowlisted, or the username/password is wrong
Outbound: connects but no audio, or one-way audio	Firewall on the carrier side blocking RTP. Media doesn’t come from the signalling address — see Regions and edges
Caller sees the wrong caller ID	The carrier is overriding the From header; ask them to pass it through

What you pay

Talkif charges its SIP per-minute rate (lower than for Talkif-purchased numbers, because the carrier leg is yours) plus the AI usage. No monthly rental — the number is your carrier’s. Rates: Credits and pricing.

Instead: your own Twilio account

If your numbers are already in Twilio, connect the account and use them directly — no SIP configuration at all.

Add a Twilio provider

Phone Numbers → Providers → Add → Your Twilio Account. Enter the Account SID and Auth Token from the Twilio Console. The token is encrypted at rest.

Pick the numbers to bring

Talkif lists the voice-capable numbers on your Twilio account. Register the ones Talkif should answer or call from.

Connect flows

Same as any number. Twilio continues to bill you for the numbers; Talkif bills its per-minute rate and AI usage.

Registering never moves a number out of your Twilio account. Removing the provider later asks whether to keep the numbers in Twilio (Talkif simply forgets them) or release them from Twilio.

Talkif configures the voice webhook on each registered Twilio number so inbound calls reach it. If you also use that number with other Twilio applications, the webhook will now point at Talkif.

Regions and edges

Where signalling and media come from, and which edge your trunk lands on.

Inbound and outbound routing

Connect flows and choose from-numbers.