How to switch mobile network (and leave your contract early): the complete UK guide

Switching mobile network in the UK takes three free text messages and, once your new provider has your code, no more than one working day. You keep your number if you want to, your old contract closes automatically, and you can't be charged for a notice period that runs past the switch date.

The switch itself is the easy part. The part that costs people money is timing: leaving a few weeks early can mean an exit fee bigger than the saving, while staying a few months too long can mean paying for a phone you already own. This guide covers both: the steps, and the maths behind "should I go now or wait?".

Switch in three texts: the quick version

1. Check where you stand. Text INFO to 85075 from the phone you want to move. Your network replies with your contract end date and what it would cost to leave today. It is free and doesn't start a switch.
2. Choose your new deal. Check coverage at your home and work postcodes on Ofcom's Map Your Mobile, then pick a plan. Our network comparison shows price rises, roaming and eSIM for 21 brands.
3. Get your switching code and hand it over.
   • To keep your number: text PAC to 65075.
   • To get a new number: text STAC to 75075.

   Give the code to your new provider when you order. They arrange the switch, and your old service stops when the new one starts.

That's it. A PAC is valid for 30 days, so you can request it before you've decided and still have time to shop around.

What switching costs

The rules that protect you

Should you leave now or wait?

Leave now or wait?

Compare two choices over the same period: leave now and pay any exit fee, or stay until your minimum term ends and move then. Nothing you type leaves your browser.

Here's the uncomfortable truth the sums usually confirm: while you're still in your minimum term, leaving early rarely saves money on airtime alone. UK networks work out exit fees from the monthly charges you have left, minus a small discount (typically 2–4%). So you pay almost all of the remaining contract anyway, then pay for the new deal on top.

There are four exceptions, and they're worth knowing:

1. Your provider has made a change or price rise that wasn't in your contract. You can usually leave without an exit fee if you act within a month of being told.
2. Your network's exit fee is unusually low. giffgaff charges 50% of the plan price for each full month left; Tesco Mobile removes VAT and takes off a further discount (about 20% in total).
3. The new deal saves you money elsewhere, for example avoiding roaming fees on a long trip abroad.
4. You're within a few days of the end date. Then the exit fee is small, and you may prefer the new deal's start date.

Worked examples

These use each network's own published method (see Leaving early for the formulas). The "new deal" is a SIM-only plan with no annual rises.

Illustrative prices; exit fees from the networks' own worked examples and published rules, checked 8 November 2026.

How the calculator works

The calculator compares two choices over the same period: leaving on the date you enter, or staying until your minimum term ends and moving to the same new deal then. It doesn't search every possible date for the cheapest day; it compares those two.

• Staying adds up your current monthly price until the end date, including any rise you enter from the date it starts, then the new deal from the end date. Part-months are charged pro rata.
• Leaving adds the exit fee to the new deal from the date you leave.
• The exit fee is the figure you enter, ideally from your INFO or PAC text. For EE, O2 airtime plans, Vodafone, Three and giffgaff 18-month plans, it can instead estimate the fee from the network's published method, clearly labelled as an estimate. If you don't know the fee, it isn't treated as zero: the calculator tells you the exit fee below which leaving now would be cheaper.
• A change you didn't agree to is shown as a separate result ("if your right to leave is confirmed"), with an indicative deadline one month after the notice. It never removes the exit fee automatically, because only your provider's notice and contract can confirm the right.
• A separate device plan is owed whichever you choose, so it isn't part of the cost difference. If leaving early makes the balance due at once, it appears in the cash you'd need on the day.
• The calendar file (.ics) is created in your browser and downloaded straight to your device. We don't send reminders and don't store anything.

What about the phone?

If your phone is on a separate device plan, leaving the airtime doesn't make the phone free, and some networks want the whole balance at once if you leave early:

A balance becoming due isn't an extra cost: you'd pay it anyway. It's a cash-flow question. If you can't pay it in one go, wait for the 24-month point or the end of your term.

Step 1: Check where you stand (text INFO to 85075)

Text INFO to 85075 from the number you want to check. Under Ofcom's switching rules your network must reply within one minute (for residential customers), and the reply must be accurate on the day it's sent. It should tell you:

• the total you'd have to pay to leave today (your early termination charge, if any);
• for pay-as-you-go, any credit left on your account;
• whether you have a separate device plan, how much is left to pay on it and when the payments end (required under the rules in force from 8 April 2026);
• a link to log in to your account.

If anything looks wrong, check it against your account or contract summary.

INFO doesn't start a switch and costs nothing. Send it whenever you're unsure whether you're still in contract.

You'll also get an end-of-contract notification from your provider 10 to 40 days before your minimum term ends. By Ofcom rules it must show your end date, what you pay now and what you'll pay afterwards, how to leave, and your provider's best deals, including at least one SIM-only deal if your phone is bundled. Out-of-contract customers must get best-deal information at least once a year.

Step 2: Choose what you're switching to

Three checks stop most switching regrets:

1. Coverage where you spend your time. Put your home and work postcodes into Ofcom's Map Your Mobile. It shows indoor and outdoor predictions and a performance score from real users. Remember that cheaper brands use one of the three big networks' masts: see which network each brand uses.
2. How much data you actually use. Look at your last three months in your phone's settings or your network's app, and pick a plan with a little headroom, not the biggest allowance on offer.
3. What the price will be in a year. Check for mid-contract price rises. Big networks add a fixed rise each spring, currently £1.80–£2.50 a month on most plans and £4 on EE handset plans; several smaller brands promise no rises, and 30-day rolling plans let you leave if prices change. See price rises by network.

Step 3: Get your switching code

To keep your number: text PAC to 65075

You get a Porting Authorisation Code (PAC), valid for 30 days, plus the same information as an INFO text (including any exit fee). The reply must arrive within one minute.

To get a new number: text STAC to 75075

You get a Service Termination Authorisation Code (STAC). It closes your old account when your new service starts, so you don't pay for both, but your old number isn't transferred.

Network quirks worth knowing

Step 4: Make the switch

1. Order your new SIM or eSIM and give the new provider your PAC or STAC (at checkout, or later in its app).
2. Activate the new SIM. Many providers give you a temporary number until the port completes.
3. Pick your switch day. The switch must complete within one working day of activation or submitting the code, whichever is later, unless you choose a later date. Requests late in the day or at weekends usually roll to the next working day. giffgaff, for example, counts a request made after 5pm as the next day's, so the switch happens the working day after that; it usually completes by 5pm, occasionally as late as 9pm.
4. Your old service stops on the switch day. Your old provider can't charge you for any notice period after that date. You pay any exit fee once, on your final bill.

Any loss of service on switch day shouldn't last longer than one working day. If the switch is late, your provider must pay reasonable compensation and explain how to claim it. For mobile there's no fixed daily amount, but Ofcom's guidance says it should include the daily share of what you pay.

Leaving a contract early

How early termination charges are worked out

Ofcom's guidance says an exit fee should start from the monthly charges you have left, then deduct a reasonable estimate of the costs your provider saves and the benefit of being paid early. A fee higher than that is likely to be treated as unfair. Ofcom fined EE £6.3 million in 2018 partly because its exit fees ignored customers' monthly discounts.

Each network publishes its own method:

The INFO text gives you the exact figure for your account on the day, so use that rather than working it out yourself. Methods checked on 8 November 2026 on each network's own help pages and price guides (iD Mobile's page couldn't be read).

Your right to leave free after a change you didn't agree to

If your provider changes your contract in a way that wasn't set out when you signed (including a price rise that wasn't stated upfront in pounds and pence), Ofcom's rules say:

• it must give you at least one month's notice, in writing or by email or text;
• you can then leave without an exit fee, as long as you do so within one month of being told (Ofcom expects at least 30 days);
• if your phone is on a separate device plan or loan, you still owe what's left on it.

The right doesn't apply to price rises that were set out clearly when you signed (for example "+£2.50 a month every April"), to changes purely in your favour, to purely administrative changes with no negative effect, or to changes directly imposed by law (such as a change in VAT).

How to use it: note the date of the notice, choose your new deal, and send PAC or STAC well within the month. If your old network still charges an exit fee, complain in writing and quote the notice. Template:

In October 2025, after O2 told existing customers that their April rise would be bigger than the amount set out when they signed (reported as £2.50 a month instead of £1.80), Ofcom said customers facing a rise beyond what they agreed must be given notice and be able to leave without penalty.

What the Telecoms Consumer Charter changes (and what it doesn't)

On 11 February 2026 the Government and the biggest providers agreed a voluntary Telecoms Consumer Charter. Signatories include BT Group (EE), Virgin Media O2, VodafoneThree and Sky, along with several broadband providers. They commit that:

• where a contract includes a mid-contract price rise, the core price you sign up to is the price you'll pay, except for "unforeseeable and externally driven events";
• April 2026 was the last rise for customers still on old inflation-linked terms; those contracts move to pounds-and-pence rises;
• end-of-contract and best-deal notices will be in plain English, switching will stay simple, and social tariffs will be easier to find;
• customers in financial difficulty can move to cheaper packages without penalty, or agree manageable payment plans.

What it doesn't do: it isn't law, it doesn't cap the size of rises written into new contracts, and it creates no new right to leave. Smaller brands such as iD Mobile, Lebara, Lyca Mobile and Utility Warehouse aren't signatories, and the Charter doesn't say whether sub-brands like giffgaff, Smarty or VOXI are covered. Ofcom published an initial assessment of its 2025 price-rise rules on 26 February 2026 and plans a full review in 2027, so check Ofcom's website for the latest position.

Out of contract? Do this today

If your minimum term has ended, you can leave at any time without an exit fee, and every month you stay on an old bundled price may be costing you money.

1. Find your real airtime cost. If your phone came with your contract, part of your bill was paying for it. Compare what you pay now with SIM-only plans offering the same data, and see what each network does when a contract ends.
2. Decide whether to keep your phone. If it works well and still gets security updates, SIM-only is almost always the cheapest move. If you want a new phone, work out the true cost first.
3. Give your current network one chance. Ask for its best SIM-only price. If it can't match what you've found, text PAC to 65075 and go.

A haggling script that respects your time

You don't need to call: most networks let you chat in their app. If the offer isn't better, you've lost five minutes; you never need permission to leave.

eSIM, dual-SIM and family lines

Switching with an eSIM

An eSIM is a digital SIM built into your phone. Switching works the same way: you request a PAC or STAC by text, then give it to your new provider, which sends you a new eSIM (usually through its app or a QR code). Don't delete your old eSIM until the new one shows signal and your number has moved across. Most UK networks and many cheaper brands now support eSIM, but a few limit it by device or sign-up channel: see the eSIM details by brand.

Dual-SIM phones

Many phones take two SIMs (two eSIMs, or one physical SIM and one eSIM). That lets you try a new network's signal at home and work before you move your main number. Some providers sell cheap 30-day plans that make a useful trial.

Switching several lines

Every number has its own PAC, and a text request covers only the number it's sent from. If you have several numbers on one account, Ofcom says you may need to ask online or by phone instead; its rules let providers handle requests for 2 to 24 numbers that way. Family or multi-line discounts can disappear when one line leaves, so check the price of the lines that stay behind before you move one.

Don't lose these when you switch

Most switches go smoothly, but these are the things people most often wish they'd sorted first.

• Two-factor codes and bank security. Your number moves with you, so SMS codes keep working, but there can be a gap of a few hours on switch day. Avoid switching on the day you need to log into banking or pay a big bill, and where you can, move important accounts to an authenticator app.
• WhatsApp and other apps. They're tied to your number, not your network, so nothing changes if you keep your number. If you're getting a new number, use WhatsApp's "Change number" feature before the old SIM stops working.
• Contacts saved to the SIM. Copy them to your phone or cloud account first.
• Voicemail. Saved voicemails stay with your old network and will be lost. Save anything you need.
• PAYG credit. Unused credit doesn't move with you. Use it up or ask your network about a refund before you switch.
• Wi-Fi calling and 4G calling. Check your phone supports both on the new network, especially if indoor signal is weak at home.
• The old SIM. Keep it in a drawer until the switch completes, in case you need to troubleshoot.

Troubleshooting

If you need to complain

1. Complain to your provider first, in writing or through its complaints process, and keep a record of dates.
2. Escalate to the ombudsman scheme your provider belongs to if it isn't resolved. For complaints raised on or after 8 April 2026, you can go to the scheme after six weeks (it used to be eight), or sooner if your provider sends a "deadlock" letter. You must apply within 12 months of the deadlock letter. It's free for you.
3. Complaints about a device credit agreement (the phone part of a split plan) can go to the Financial Ombudsman Service.

Source: Ofcom's list of approved ADR schemes, updated August 2026. Check your provider's complaints code for the current scheme before you apply.

Frequently asked questions

How long does it take to switch mobile network?

Once your new provider has your PAC or STAC and your new SIM is active, the switch must complete within one working day, unless you pick a later date. Requests late in the day or at weekends usually move to the next working day.

Can I switch network if I still owe money on my phone?

Yes. If your phone and airtime are one bundled contract, you'll pay an exit fee for the months left. If the phone is on a separate device plan, that plan carries on, and with some networks (O2 Refresh in the first 24 months, EE, and Tesco Mobile in the first 24 months) the whole remaining balance becomes due when you leave.

Will I lose my number or signal while switching?

Not if you use a PAC: your number moves with you. Any break in service on switch day shouldn't last more than one working day, and is usually a few minutes or hours. Keep your old SIM until the switch completes.

Do I need to unlock my phone to switch?

Usually not. UK networks have been banned from selling locked phones since 17 December 2021. If you have an older phone that is locked, ask your old network to unlock it before you switch.

Does switching network affect my credit score?

Taking out a new pay-monthly contract or device plan usually involves a credit check, which shows on your credit file. Most rolling SIM-only plans need only a light check or none. Switching itself, and closing an account in good standing, doesn't harm your score.

Can I switch if my provider raised my price mid-contract?

If the rise was set out in your contract when you signed (for example a fixed amount every April), you'll pay the normal exit fee. If it wasn't, you can usually leave without an exit fee within one month of being told.

What if my PAC code has expired?

Ask for a new one by texting PAC to 65075 again. It's free, and nothing has changed with your old contract.

Can I switch an eSIM to another network?

Yes. Request a PAC or STAC as normal, get a new eSIM from your new provider, and only delete the old eSIM once your number has moved.

Is it worth haggling with my current network first?

If you're out of contract, it takes five minutes and sometimes wins a better price. Go in knowing the deal you'd switch to, and don't sign up to a new long contract unless the total cost beats it.

Do I have to tell my old network I'm leaving?

No. Texting for your PAC or STAC is all the contact needed, and your new provider handles the rest. Your old account closes automatically on the switch day.

Sources

All checked on 8 November 2026.

• Ofcom: Switching mobile phone provider
• Ofcom: General Condition C7 (switching), unofficial consolidated version
• Ofcom: guidance on early termination charges
• Ofcom: guidance on contract modifications and the right to exit
• Ofcom: statement on O2 price rises (October 2025)
• Ofcom: end-of-contract and best-tariff notifications statement
• Ofcom: approved ADR schemes and quicker complaints resolution from 8 April 2026
• Ofcom: guidance on compensation for switching and porting delays
• GOV.UK: Telecoms Consumer Charter
• Network pages on exit fees: EE, O2, Vodafone, Three price guide, Tesco Mobile, giffgaff terms, Sky
• Three: about your final bill (device plans)
• giffgaff: keeping your number when you join

About this guide

We checked every rule and network method in this guide against Ofcom, GOV.UK and the networks' own pages on 8 November 2026. Where we couldn't read a page, we say so. MobiSaver has no affiliate links or advertising, so we don't earn anything if you switch, or if you stay. This guide is general information, not legal advice.