Sipflex

BRING YOUR OWN PBX

UK trunks for systems you control.

Connect an existing PBX using registration, IP peering or IAX2. Sipflex supplies the UK numbers and calling capacity; your PBX remains yours.

  • £2 per number
  • One complimentary account channel
  • PJSIP, peering and IAX2
  • Detailed configuration guides

PRIORITY PLATFORMS

Choose your PBX.

These pages focus on provider settings and known interoperation, with clear boundaries around customer-controlled configuration.

AS

Asterisk

PJSIP registration, IP-authenticated peering and IAX2 with copyable configuration examples.

View compatibility
FP

FreePBX

Current PJSIP and IAX2 guidance for FreePBX administrators managing their own system.

View compatibility
3C

3CX

Registered SIP trunks, pilot-number routing and DDI configuration using the Generic SIP Trunk template.

View compatibility
I2

IAX2

A first-class IAX2 service for Asterisk, FreePBX and compatible open telephony platforms.

View compatibility

ANOTHER SIP PLATFORM?

Generic SIP is welcome.

Sipflex is not limited to the PBXs listed above. If your system supports standard SIP registration or IP peering, you can configure it using the settings shown in your portal.

View generic SIP settings

30-DAY FREE TRIAL

Connect your system to Sipflex

Start testing with your own PBX, application or voice platform.

Start free trial

No card required.