Switch-off 2027
How to port your UK phone number to VoIP: STAC and PAC, step by step
PSTN switch-off2026-05-036 min readBy Silux Call team
PAC, STAC, and the timelines that actually apply. The exact steps to move a UK landline or mobile number to a VoIP provider without losing a single call.
Landline (STAC)
- Request your STAC code from your current provider. Free, must be issued within one working day under Ofcom rules.
- Give the STAC + your billing address to Silux Call.
- We submit the port. It typically completes in approximately 14 working days, and your old line keeps working until then.
- Test before you cancel anything.
Mobile (PAC)
Text PAC to 65075 from the SIM you want to port. You receive a PAC code within a minute. Give the PAC to Silux Call within 30 days.
Common gotchas
- Outstanding contract — your old provider must clear early-termination fees first.
- Address mismatch — keep the old bill address until the port completes.
- Multi-DDI ranges — port the whole range with one submission, not number-by-number.
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