Can I Keep My Business Phone Number When Switching?

Yes. You can keep your UK business mobile or landline number when switching provider. For a mobile number you request either a PAC (Porting Authorisation Code) if you are moving the number, or a STAC (Switching and Cancellation Code) if you only want to cancel — obtained free by texting PAC or STAC to 65075. The port typically completes in one working day. Landline numbers port via a separate process called Notification of Transfer (NoT), coordinated by your new provider and usually completing within 10 working days.

Keeping your number protects business continuity — customers do not need to update records, your stationery stays valid, and you do not lose incoming leads during the switch. The process is free, legally guaranteed by OFCOM, and works across all UK networks.

At Compare The Networks, we manage hundreds of business number ports each month. This guide covers exactly how to keep your mobile or landline number when you switch provider, the timelines, and the common pitfalls that cause ports to fail.

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Quick Comparison: PAC vs STAC vs NoT

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How to Keep a UK Business Mobile Number (PAC Process)

1. Text PAC to 65075 from the business mobile you want to move. This works on EE, Vodafone, O2, Three, Tesco Mobile, Sky Mobile, and virtually all UK MVNOs.
2. Receive the PAC within 1 minute by SMS. The code is valid for 30 days. The message also includes any early termination fees, outstanding charges and credit balance.
3. Give the PAC to your new provider when you sign up. They will schedule the port for the next working day after receipt.
4. On port day, your old SIM stops working and your new SIM takes over the number. There is typically a 1-2 hour outage window.
5. Check incoming calls and SMS after port day. If anything fails, contact the new provider within 48 hours — OFCOM rules require them to resolve porting issues quickly.

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How Porting Works for Multiple Business Mobile Lines

If you are moving 5, 20 or 200 SIMs, the process scales but is slightly different:

• Your new provider will usually handle the port paperwork as a multi-line port. Each line still needs its own PAC code.
• Some networks let account managers request PACs in bulk via the business portal rather than by individual SMS.
• Plan a port date when downtime is tolerable (early morning, weekend, or before a public holiday). All lines usually port at the same time, so a 1-2 hour outage hits everyone.
• Ensure email and voice continuity — consider tempoprary call forwarding to a landline or softphone for critical numbers during the port window.

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How to Keep a UK Business Landline or VoIP Number

Landline and VoIP porting works differently from mobile. You do not need a PAC. Your new provider requests a Notification of Transfer (NoT) from your current provider on your behalf. The process:

1. Sign up with your new provider and supply the number(s) you want to port along with the current provider name.
2. New provider submits the NoT to your current provider through Openreach or their own porting system.
3. Current provider validates the request (usually within 3 working days). They cannot refuse a valid port request.
4. Port date agreed. Landline ports are typically scheduled 10 working days after the NoT is accepted, though some complete in 5 working days.
5. On port day the number transfers. If the new service is hosted VoIP, calls start ringing your new handsets or softphone immediately.

A few quirks to be aware of:

• Geographic numbers only port within the same area code area. A London 020 number cannot become a Manchester 0161 number, and vice versa.
• Non-geographic numbers (0800, 0330, 0345) port differently and require specific authorisation from the number range holder.
• Some older FTTC/PSTN lines cannot port directly to VoIP without an interim step. Ask your new provider if your line has any porting restrictions before you sign up.

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Common Pitfalls That Cause Business Number Ports to Fail

1. Outstanding balance on the losing account. Some providers will block the port until the final bill is paid. If you are in dispute, get the dispute resolved (or paid under protest) before porting.
2. Wrong account holder name. The losing provider will reject the port if the business name on the port request does not match their records. Double-check exact registered business name, trading name, and account holder.
3. Expired PAC. PACs are valid for 30 days. If you sit on the code, you will have to re-request.
4. Number already ported. Sometimes a number has been ported before, and the losing provider's records are out of date. Your new provider can escalate with OFCOM if genuinely stuck.
5. Port scheduled for a day the business is closed. If no one tests the new SIMs on port day, you can lose calls for a day before anyone notices. Always schedule ports during business hours.
6. Multi-line ports with mixed contract end dates. Every SIM still needs its own PAC and may have its own early termination fee. Run the numbers before committing to a bulk port.

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What Does It Cost to Keep Your Business Number?

• The PAC / STAC / NoT itself is free. OFCOM rules prohibit charging for these codes.
• Early termination fees still apply if you are mid-contract. The text response to PAC or STAC request includes the ETF.
• New provider setup fees may apply (some charge £5-£15 per line activation) — but the number transfer itself is no extra cost.
• Lost credit balance — if you have credit on the old account, it is usually forfeited when you port. Transfer credit to another line or use it up before porting.

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Does My Business Have the Right to Keep Its Number?

Yes. Under OFCOM General Condition C7, all UK telecoms providers must let customers port their number to another provider on request. This applies to both mobile and landline services, consumer and business contracts. A provider cannot refuse a legitimate port request, though they can delay it by a few days to complete validation.

If a provider refuses to issue a PAC, delays beyond the one working day rule, or charges for the port, you can escalate to CISAS (for most providers) or Ombudsman Services: Communications (for others) after the provider's internal complaints process has run its course. See our escaping a mis-sold business mobile contract guide for the full complaint escalation route.

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Switching Provider: The Full Process (With Number Kept)

1. Get comparison quotes — 3+ providers for apples-to-apples comparison. Free quote here.
2. Accept the best offer and sign the new contract. Most activation is conditional on successful port.
3. Request your PAC (mobile) or give the new provider your landline number (fixed line). Do NOT give the PAC to anyone other than your chosen new provider.
4. Agree a port date with the new provider. Aim for a quiet business day.
5. Test on port day — make and receive calls, send and receive SMS, check voicemail, check data.
6. Close the old account (mobile STAC is automatic once the port completes; landline cancellation happens when NoT completes).
7. Check the final bill from the losing provider for any unexpected charges.

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When Is It Better NOT to Keep Your Business Number?

In a few scenarios, starting fresh with a new number is actually better:

• Rebranding. If the business is changing name, memorable new numbers may outperform legacy ones.
• Escaping a spam-flagged number. If your old number has been reported as spam (e.g. used heavily for cold calling and flagged by Truecaller or Hiya), start fresh.
• Geographic mismatch. If you have moved offices and your old landline area code no longer reflects your location, a new number may be worth it.
• Simpler, more memorable numbers available. Some providers offer choice of number — a round number can be worth forfeiting the old one.

Most businesses, though, benefit from keeping the number. It is the default recommendation.

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Frequently Asked Questions

Can I keep my business mobile number when I switch provider in the UK?

Yes. Text PAC to 65075 from the line, give the code to your new provider, and the number transfers — typically within one working day. This works on every major UK network including EE, Vodafone, O2 and Three.

How long does it take to port a UK business mobile number?

One working day is standard for mobile ports. The PAC is issued within a minute of requesting it, and the new provider schedules the port for the next working day after they receive the code.

How long does it take to port a UK business landline number?

Typically 10 working days, though some VoIP providers complete simple ports in 5 working days. The process uses a Notification of Transfer (NoT) rather than a PAC — the new provider handles it on your behalf.

What is the difference between a PAC and a STAC?

A PAC (Porting Authorisation Code) is used when you want to keep your mobile number and move it to a new network. A STAC (Switching and Cancellation Code) is used when you want to cancel your contract and do not want to keep the number. Both are free, issued within a minute by text, and requested by texting PAC or STAC to 65075.

Does porting my business number cost anything?

No. The PAC, STAC and NoT codes are all free by OFCOM rules. Early termination fees on your old contract (if mid-term) still apply, and the new provider may charge a small activation fee, but there is no charge for the number transfer itself.

Can I port my business number if I am mid-contract?

Yes. You can port at any time, but if you are inside the minimum contract term you will pay an early termination fee to the losing provider. The ETF is usually the remaining monthly line rental for the contract term. Check the exact fee before porting — some providers are more aggressive than others.

Can I port a business number that is in the company name?

Yes. The port request must match the account holder details on the losing provider's records — usually the registered business name. Have your company number, registered name and an account authority letter ready if the losing provider asks for them.

What happens if the port fails on the scheduled day?

The new provider is responsible for fixing it. OFCOM rules require same-day resolution of port failures. Keep the old SIM active (do not destroy it) until you are sure incoming calls are reaching the new SIM. If the problem persists beyond 48 hours, escalate to the new provider's complaints team.

Can I port my number to a VoIP system?

Yes. Both mobile and landline numbers can be ported to VoIP. Some mobile MVNOs and VoIP providers specialise in hosting ported mobile numbers so you can receive mobile calls through a VoIP app. Landline-to-VoIP porting is the standard path for most UK businesses migrating before the 2027 PSTN switch-off.

Can I port a business number from an administrator if the company is insolvent?

This is more complicated. An administrator or liquidator can authorise a port, but the losing provider may require court or administrator documentation before processing. Allow extra time — 2-3 weeks is realistic rather than the normal 1 day for mobile.

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Switch Your Business Mobile Without Losing Your Number

We port numbers every day, for single-line sole traders and 200-line fleets. We handle the paperwork, agree the port date, and coordinate with both the losing and gaining providers so you do not lose calls.

Get a free business mobile quote. We will include the port cost estimate and full number-keeping process in the proposal.

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Compare The Networks is a trading name of Xtra Phones UK Ltd, an OFCOM-regulated comparison service. Porting rights are guaranteed by OFCOM General Condition C7. Information accurate as of April 2026.