By Compare The Networks editorial team. Published 2026-10-06. Content reviewed 2026-10-06.

How Do You Switch Several Business Mobile Numbers?

Switching several business mobile numbers starts with an accurate line list and an authorised account contact. Agree the transfer plan with both providers before distributing SIMs or changing staff instructions.

The objective is simple: each employee should know which SIM belongs to them, what happens on the transfer day and who can help if their number does not work. The preparation is more important than the size of the spreadsheet.

Check which switching route applies

Ofcom's mobile switching guidance distinguishes a single number, two to 24 numbers, and more than 24 numbers. For two to 24, request the PAC online or by phone; for larger simultaneous transfers, contact the existing provider for its process.

A PAC is valid for 30 days. Check the agreed transfer date against that window and confirm any charges associated with leaving the existing agreement. Keeping the number does not settle separate contractual balances.

Build a line list before requesting the codes

Record the mobile number, current user, account reference, intended new SIM or eSIM, and whether the number should move. Include spare phones, shared duty numbers and lines assigned to staff on leave.

An invoice tells you what is being billed; it may not tell you who has the handset today. Compare the bill with your staff list and physically check any uncertain connection. A forgotten shared phone is easy to miss until customers stop reaching it.

Store this list securely and share only the details each employee needs. Avoid sending a full staff-number spreadsheet to the whole company.

Agree the sequence with the new provider

Ask whether the proposed move will happen as one batch or in stages. Confirm any submission cut-off and which dates are suitable. If the business has a customer-support duty phone, make its continuity arrangements explicit.

Choose a period when your administrator and affected staff can be contacted. Avoid a critical sales event or a day when the person with account access is travelling. If a transfer must happen then, agree the contingency before proceeding.

Check the phones as well as the numbers

Confirm that the existing phones accept the proposed SIM arrangement. For eSIMs, ask how activation details will reach the intended user and whether setup needs an internet connection. Test a representative device before repeating the instructions across the team.

Back up important material using your normal business process. List services that send sign-in codes to the number and plan how employees will access them during the transition. Keep a support contact somewhere other than the phone being switched.

Give staff a short transfer-day instruction

Explain what they should do before the transfer, when to change or activate the SIM and how to report a problem. Use the actual provider's instructions. Do not ask staff to improvise settings because a colleague's phone worked differently.

Once the number appears active, test incoming and outgoing calls, a text message, mobile data and voicemail. Check the number seen by a recipient. Record the result against the individual line rather than marking the whole batch complete after one successful call.

Reconcile the bills after the move

Check the final bill from the old provider and the first bill from the new one. Match each charge to the agreed line list and dates. Query unexplained items with the relevant bill and written terms attached.

Keep the completed transfer record for the next renewal. It becomes a useful asset when the business grows or another administrator takes over.

For a tailored comparison, use the business mobile quote checklist alongside your line list.