How to Change Your Phone Number in the UK (Get a New Number + What Happens to the Old One)

Dec 22, 2025

Want to get a new phone number in the UK? The right method depends on one thing: do you want to keep your current number, or do you want a brand new one?

Quick answer

You have three routes:

  • Staying with the same provider: request a number change (new number on your current SIM/eSIM).
  • Switching provider + keeping your number: request a PAC and give it to the new provider (PAC code explained).
  • Switching provider + getting a new number: request a STAC so your old service ends and you start fresh.

Official rules and timelines: see Ofcom’s switching guidance: www.ofcom.org.uk

Best upgrade: if you want to choose a memorable number (not random), browse UK mobile numbers by pattern or request a bespoke number.

1) PAC vs STAC vs number change

What you want Do this Who you contact What happens next
Keep your number, switch networks PAC Your current provider for the PAC, then your new provider to port Your number moves to the new provider; old service ends at the switch.
New number, switch networks STAC Your current provider for the STAC, then your new provider Your old service is terminated; you start on a new number.
New number, stay with the same network Number change Your current provider Your SIM/eSIM gets a new number; the old number stops being yours.

2) PAYG vs contract: what’s different?

If you’re on PAYG (pay as you go)

  • Switching is usually straightforward because there’s no long contract term.
  • Any remaining credit may not move with you; check your provider’s policy before switching.
  • If you rely on your number for important logins, a PAC (keep number) is usually safest.

If you’re on a contract

  • If you leave early, you may have early termination charges (your provider should show switching information with your PAC/STAC).
  • Most people avoid headaches by following the official switching process and not cancelling early.
  • Ofcom explains switching rules, timelines and protections here: www.ofcom.org.uk

3) Option A: change your number with the same provider

This is the fastest way to get a new number if you’re not bothered about switching networks.

  1. Log into your provider account (app/website) or contact support.
  2. Ask for a number change (some systems call this “change number” or “replace number”).
  3. Restart your phone (and re-download eSIM if your provider asks).
  4. Update your number everywhere it’s used (banking, WhatsApp, 2FA, delivery apps, etc.).
Tip: If you need a number that looks good on marketing or is easier to remember, you’ll usually do better by choosing the number first (see section 8).

4) Option B: switch provider and keep your number (PAC)

This is the best route if your number is already linked to banking, WhatsApp, clients, adverts, or business listings.

  1. Request a PAC from your current provider (for one number, most people text PAC to 65075).
  2. Order/activate your new SIM or eSIM.
  3. Provide the PAC to your new provider during activation.
  4. Keep the old SIM active until the transfer completes.
  5. Test calls/SMS/data once the port completes.

Full guide: PAC code explained

5) Option C: switch provider and get a new number (STAC)

If you want a clean break and do not want to keep the old number, use a STAC.

  1. Request a STAC from your current provider (for one number, many people text STAC to 75075).
  2. Provide the STAC to your new provider during sign-up/activation.
  3. Your old service ends and you start with a new number on the new SIM/eSIM.
  4. Update important logins and contacts with your new number.

6) Timeline: what happens on switch day?

The exact schedule varies by provider, but a typical “switch day” looks like this:

  • Before the switch: your old SIM works normally.
  • During the port window: your old SIM may lose signal first (this is normal).
  • After completion: your new SIM/eSIM works and your number is live.

How to avoid double charges

  • Use the official switching process (PAC/STAC) and provide the code to the new provider.
  • Don’t cancel early unless you are sure you understand the impact on billing and service end dates.
  • Keep the old SIM active until the switch completes.

Ofcom switching guidance (rules, timing, protections): www.ofcom.org.uk

7) What happens to your old number?

  • If you use a PAC: your number moves to the new provider and remains your number.
  • If you use a STAC: your old number does not move; the old service ends and the number may eventually be recycled.
  • If you change number with the same provider: your old number stops being yours and you must update any accounts that use it.

8) What to update checklist

If your number changes (number change or STAC), update the essentials immediately to avoid being locked out.

Account + security checklist

  • Banking apps + SMS verification
  • WhatsApp (change number feature) + any messaging apps tied to your SIM
  • Email accounts (Gmail/Outlook) recovery + 2FA
  • Apple ID / Google account recovery phone
  • Password manager recovery + authenticator back-ups
  • Payment services (PayPal/Stripe/Apple Pay/Google Wallet alerts)
  • Delivery apps and ride-hailing (verification SMS)

Business checklist

  • Google Business Profile (phone number)
  • Website contact page + header/footer phone number
  • Ad accounts and call extensions (Google Ads / Meta)
  • Printed materials: business cards, flyers, packaging, invoices
  • Signage: shopfront, vans, uniforms
  • CRM records + voicemail greeting

9) If delayed: what “delayed” means (and compensation)

A short disruption during the port window can be normal. A switch is usually considered “delayed” when it goes beyond the expected switching timeframe for your case.

  • Contact the new provider first (they control the port request) and ask for the scheduled port window and escalation.
  • Ask whether the delay qualifies for automatic compensation under the switching rules.
  • Use the official guidance as your reference point: www.ofcom.org.uk

10) Want to choose a better number instead of a random one?

If you’re changing your number because you don’t like your current digits (or you want something stronger for business), you can choose a memorable number first and then connect it to your preferred UK network.

PAC codes by network

FAQ

How do I get a new phone number quickly?

The fastest route is to request a number change with your current provider, or activate a new SIM/eSIM on a new provider.

How do I keep my number when switching networks?

Use a PAC and give it to your new provider. Full guide: PAC code explained.

What’s the difference between PAC and STAC?

PAC keeps your number when switching. STAC switches provider without keeping your number.

Will changing my number affect WhatsApp and banking?

Yes. Many services use your number for verification. Use the checklist above and update your accounts as soon as your new number is active.

Can I choose my new phone number in the UK?

Standard SIMs usually assign random numbers. If you want to choose memorable digits, browse Numbers Market collections or request a bespoke number.

Browse UK Mobile Numbers Create a Bespoke Number

Also useful: PAC code explained • UK mobile networks list
Back to UK Mobile Number Guides & VIP Number Insights