How to Switch UK Mobile Network Without a Contract (2025 Guide)

What’s happening

Switching mobile networks in the UK is straightforward — especially if you’re not tied into a fixed-term contract. Thanks to Ofcom rules, you can request a code and move networks within minutes. Still, there are little annoyances and subtle steps people miss, so this guide walks you through everything I actually did (and the mistakes I made) to switch cleanly, keep my number and avoid downtime.

Who this is for

This guide is for anyone on a rolling SIM, PAYG or expired contract who wants to switch networks without penalties. It’s also useful if you favour short-term flexibility (30-day plans) and want to chase better prices or coverage.

Step 0 — Quick reality check (before you start)

Don’t assume your plan is contract-free. I learned the hard way — my provider app showed “rolling monthly” but a small line in the T&Cs revealed a minimum 3-month notice for one promotional plan. Open your provider’s app or web account and confirm “Plan type” and any “Minimum term / Contract end date”.

Step 1 — Decide: keep your number or start fresh?

This determines the code you need. If you want to keep your current number, request a PAC. If you want a new number and to close the old account, get a STAC. I kept my number — easiest when you use your phone for banking and logins.

Step 2 — Get the PAC or STAC (the fastest, official way)

UK law requires providers to give the code immediately by SMS. Do this from the SIM you want to move.

  1. Text “PAC” to 65075 — the PAC arrives by SMS within a minute and is valid for 30 days.
  2. Text “STAC” to 75075 — if you want to close the old account and take a new number with the new provider.
  3. Text “INFO” to 85075 — this returns details about your plan (useful if you’re unsure about fees or outstanding balances).

Human note: I once requested a PAC from on-line chat and waited 24 hours — don’t waste time. Use the SMS method from the SIM itself.

Step 3 — Choose your new provider (practical criteria)

When you’re contract-free, pick purely on coverage, price and extras. Ask yourself:

  • Does the new network have strong 4G/5G where I live and commute?
  • Is the deal 30-day rolling or a short fixed term I’m happy with?
  • Does the provider support eSIM (if you prefer not to wait for a physical SIM)?

I favour 30-day rolling SIMs from well-known MVNOs when testing coverage. They’re cheap, and if coverage is poor after a week I can jump ship again without charges.

Step 4 — Activate the new SIM and submit your PAC/STAC

  1. Insert the new physical SIM or install the eSIM via the provider app.
  2. During activation, choose “Transfer my number” and enter your PAC (or STAC) code when prompted.
  3. Pick the transfer date — many providers let you choose next working day; some will do it instantly.

Most switches complete in 24 hours on weekdays and often faster. If you’re transferring on a weekend, expect it to finish on the next working day in some cases.

What actually happens during the switch (expectation vs reality)

Be prepared for a short period with no service. From my experience:

  • Data on your old SIM usually stops as the transfer begins.
  • Incoming calls may fail during the handover but should route to the new network shortly after the transfer completes.
  • SMS messages for banks can take longer to arrive while routing updates propagate.

I always schedule transfers during quiet hours (late evening) to reduce the impact if something goes slightly wrong.

Step 5 — Post-switch checklist (do this immediately)

  1. Restart the phone to force network registration.
  2. Turn Mobile Data off and on to refresh APN settings.
  3. Check VoLTE and Wi-Fi Calling are enabled (Settings → Mobile network → Advanced).
  4. Open your banking and 2-factor apps — if you need to re-register, do it while you still have access to the old SIM in case an overlap is needed.
  5. Run a quick speedtest to verify coverage and speeds in your usual locations.

Common problems and exact fixes

No mobile signal after switching

Fix: Airplane mode on → wait 10 seconds → off. If still no signal, remove and reinsert the SIM, restart the device, then check the provider’s APN page and manually enter the APN if necessary.

Mobile data works but calls or texts fail

Fix: Ensure the number porting has finished (allow up to 24 hours). Check VoLTE and Emergency Calling settings. If texts from services (e.g., bank codes) are missing, wait a few hours — SMS routing updates slower than data.

Number hasn’t transferred after 24 hours

Fix: Contact the new provider first — they can push the transfer. If that fails, contact your old provider with the PAC/STAC reference and ask for status.

Practical tips to avoid common pitfalls

  • Don’t cancel your old account before the transfer — cancelling can void the PAC and complicate the switch.
  • Keep the old SIM until the transfer completes: you might need it for SMS or verification codes.
  • Watch for PAC validity — it’s typically 30 days; request a fresh PAC if you miss that window.
  • If you use dual-SIM, set the new SIM as the default for data only after the transfer confirms.

Why switching is easier in 2025

Ofcom’s rules mean providers must give codes instantly and cannot obstruct switches. That’s why I’ve switched three times in the last 12 months chasing better 5G coverage and never paid a penny in exit fees.

Quick test I use to confirm a successful switch

  1. Call a friend’s phone and ask them to call you back — confirms inbound/outbound voice routing.
  2. Send and receive an SMS to verify text routing.
  3. Run a Speedtest in your local area to confirm expected speeds and latency.

When to get extra help

If you run into billing disputes, unexpected charges or the transfer stalls beyond 48 hours, escalate to the provider’s complaints line and keep screenshots of PAC messages and activation screens. Ofcom can intervene if a provider refuses a lawful switch.

Post a Comment