Why most people still overpay (and how the switch process changed)

Ofcom data has consistently shown the same pattern for years: UK mobile customers who never switch pay around £100 to £180 more per year than those who shop around once a year, simply because plans get cheaper for new customers while loyal ones stay on the old price. The cheapest part of the market, SIM-only plans from MVNOs, has barely changed in price since 2019, yet the average mid-contract handset deal has risen sharply.

Ofcom's Text-to-Switch rules went live on 1 July 2019 and removed the worst friction from the old process. You no longer need to call your network, sit on hold, justify yourself to a retentions agent or hand over notice. A free text gets you a switching code within one minute, and the new provider handles everything else.

Notice-period charges were banned at the same time. Your old provider can charge you for the remainder of your contract if you are mid-term, but it cannot charge an extra month for "notice". The early exit fee, if any, is calculated to the day you switch.

Which switching text should you send?

Three quick questions and the tool below tells you exactly which short code to text first, what your provider will send back, and what your switch day will look like hour by hour.

Switch advisor

Your switch in 3 questions

Recommendations update live as you change your answers.

1. Do you want to keep your current phone number?

2. Are you still inside your minimum contract term?

3. Did you buy your phone on the contract?

Text to send

Reply time

~1 min

Then full switch in 1 working day.

First check

Codes verified May 2026. Source: Ofcom Text-to-Switch rules, in force since 1 July 2019.

PAC code: keep your existing number

The Porting Authorisation Code, PAC for short, is the 9-character key you hand to your new provider so they can move your phone number over to their network. To request one, text PAC to 65075 from the SIM you want to switch.

Your current provider must reply within one minute. The reply contains:

  • ✓Your PAC code (9 characters, valid for 30 days);
  • ✓Any early-exit fee for leaving mid-contract;
  • ✓Any remaining PAYG credit and whether it can be transferred;
  • ✓A reminder of when your minimum term ends.

Hand the PAC to your new provider and the port is completed by the end of one working day. Your old line closes automatically the moment the new one activates, there is no risk of running both at once.

STAC code: switch with a new number

Ofcom research showed that around one in six switchers do not want to keep their existing number, perhaps because the old line is full of cold callers, or because they are starting a new job or new chapter. For them, the Service Termination Authorisation Code (STAC) does the same job as the PAC, but without porting the number.

To request a STAC, text STAC to 75075. The reply arrives within one minute and contains your STAC, any early-exit fee, and confirmation of when your account will close.

As with a PAC, the old account closes the moment your new SIM activates, you cannot be double-billed for the same period.

INFO code: check your contract before you switch

If you are unsure whether you are still under contract, or what an early exit would cost you, text INFO to 85075. Your provider has up to two hours to reply (in practice the answer is usually under a minute) and the reply tells you:

  • ✓Your contract end date;
  • ✓Any early-exit fee you would pay if you switched today;
  • ✓Your monthly recurring charge;
  • ✓How any included handset or other devices factor in.
INFO does not trigger a switch and does not generate a PAC or STAC. It is purely informational, and is the safest first step if you suspect you might still be locked in. You can always send PAC or STAC later if the numbers add up.

Switching mid-contract: when it makes sense

Switching mid-contract is allowed, but you will owe the remainder of your minimum-term commitment. On a handset contract that usually includes the unpaid device cost, which can run to hundreds of pounds. On a SIM-only contract it is just the remaining months of the cheap monthly fee, sometimes only a few pounds.

Three situations where paying out a contract early can still save money:

  • ✓Significant material change. If your network has materially changed your contract, for example a price rise above the agreed terms, Ofcom rules require them to let you leave penalty-free within 30 days of the notification.
  • ✓Genuinely poor coverage at a new home or workplace. Most providers will accept a coverage-based cancellation if you raise it inside the first 14 to 30 days; later, you usually have to negotiate or pay the exit.
  • ✓Cheap SIM-only exit. On a £6 to £15 SIM-only deal, the remaining months of a 12-month contract can be less than a single month at a cheaper new provider, sometimes worth paying out to escape.

Network locks and unlocking

Switching the SIM is one thing; making sure the handset accepts the new SIM is another. Ofcom rules brought in on 1 December 2021 require all UK mobile providers to sell handsets unlocked, so anything bought new from an EE, Vodafone, O2 or Three store since that date is unlocked from day one.

Older handsets, refurbished devices and PAYG phones from supermarkets may still be locked. To unlock:

  1. 1Contact the network the phone is locked to, not the network you are switching to.
  2. 2Provide your IMEI number (dial *#06# on the handset to display it).
  3. 3Unlocking is free and Ofcom requires it within 72 hours, though most networks complete the unlock within minutes.

If something goes wrong: complaints and ADR

If a switch goes wrong, double-billing, the number does not move, the old line stays open, the formal complaint path runs through your provider first, then the ombudsman.

  1. 1Raise a formal complaint with the provider. Ask for a complaint reference and the expected resolution timeframe in writing.
  2. 2If not resolved in 8 weeks, or if the provider issues a deadlock letter sooner, escalate to the relevant Alternative Dispute Resolution (ADR) scheme.
  3. 3ADR schemes for telecoms are free to consumers. Your provider is contractually bound to abide by the decision; you are not. The two recognised schemes are the Communications Ombudsman and CISAS.

For automatic compensation, Ofcom\'s switching code requires providers to credit your account if a switch is delayed beyond the working-day window. Check your first bill from the new provider for any credit referencing "delayed switch".

Frequently asked questions

A PAC code is valid for 30 days from the moment it is issued. If you do not use it within that window, you must request a new one with a fresh text to 65075. Your existing contract continues as normal during that 30-day window, the clock only starts when you hand the PAC to your new provider.

Ofcom rules require the full switch to complete by the end of one working day from the moment the new provider accepts your PAC or STAC. In practice, most ports finish within hours. The old line closes automatically when the new one activates, you cannot be double-billed.

No. The provider must issue your PAC, STAC or INFO reply within the regulator's time limit; they cannot refuse, even if you owe an early-exit fee. They may try to offer retention deals when you request the code, you are free to ignore them. The text-based system was designed precisely to remove this friction.

Most UK networks do not transfer PAYG credit between providers, so use it up before switching where possible. The PAC reply text will confirm exactly how much credit will be lost. A few providers (notably Vodafone PAYG) have offered refunds of unused credit on request, ask the agent when you cancel.

No. Ofcom banned notice-period charges in July 2019 alongside the text-to-switch reforms. Your provider can charge you for the remainder of your minimum-term commitment, calculated to the day you switch, but cannot add a 30-day notice on top.

Yes, set up the new SIM or contract order first. The PAC/STAC clock starts ticking the moment you have the code, and the switch happens in one working day once the new provider accepts it. Ordering the new SIM in advance avoids a gap in service.

No. Vodafone and Three continue to issue PAC, STAC and INFO codes separately as customer brands, and the text-to-switch process is identical to before. Even within the merged VodafoneThree group, switching from one of the brands to the other is treated as a normal port.

Next steps

Before you send your text, compare SIM-only deals across the UK market to make sure the new plan is genuinely better than the old one. If you want to be sure the new network has decent reception at your address, our coverage guide walks through the Ofcom checker and a real speed test in five minutes.

For more, see all our UK mobile guides.