1. Start the trial and complete verification
The Sipflex trial lasts 30 days and does not require a payment card. Create the account using accurate customer information and complete the identity or business checks requested in the portal. Service availability remains subject to KYC and fraud controls.
2. Add a UK phone number
- Sign in to the Sipflex portal.
- Open Account → Numbers.
- Choose an available UK number and review the displayed recurring charge before confirming it.
- Keep the number in the exact format displayed in the portal; it may also be used as a SIP username depending on your connection.
Flexible capacity
Numbers and channels are separate. The account includes one complimentary concurrent channel in total; add further channels when you need more calls active at the same time.
3. Choose how your system connects
| Method | Use it when | Next guide |
|---|---|---|
| SIP registration | Your system will authenticate with a username and separate trunk password | Registration settings |
| SIP peering | Your system has a fixed public IPv4 address and authenticates by network location | Peering settings |
| IAX2 | You deliberately use Asterisk, FreePBX or another compatible IAX2 system | IAX2 options |
| Built-in platform profile | You are connecting a supported AI voice or communications platform | Platform profiles |
4. Verify the service
- Confirm registration or peering status on both sides.
- Call the Sipflex number from another network and confirm the correct inbound destination.
- Place an outbound call and verify the caller ID.
- Confirm two-way audio.
- Test DTMF through an IVR or keypad flow.
- Repeat the test with the number formats your application will use in production.
5. Know the support boundary
Sipflex provides the number, PSTN connectivity, portal controls and provider-side diagnostics. We document our settings and may offer limited advice, but we do not configure customer PBXs, devices, firewalls, applications or dial plans.