A SIM swap (also called a SIM replacement) moves your existing mobile number onto a new physical SIM or eSIM on the same network — you arrange it with that network, not by re-buying the number from Create Numbers. Use it when a SIM is lost, stolen, damaged, the wrong size for a new handset, or you are moving from plastic SIM to eSIM. This is different from number porting, which changes the hosting provider using a PAC/STAC (Number porting). Ofcom advises contacting your provider as soon as possible — ideally within 24 hours — if a phone is lost or stolen so the SIM can be barred and unauthorised spend limited (Ofcom — Lost or stolen phone).
SIM swap versus number porting
Choose a SIM swap when you want to keep the same network account and only change the SIM profile; choose porting when you want to change provider and keep the digits. Create Numbers’ role after fulfilment is as the source of the custom number (via PAC); day-to-day SIM logistics sit with whoever currently hosts the line. UK mobile remains enormous — Ofcom counted 117 million mobile subscriptions in 2024 (Ofcom Communications Market Report 2025) — so every major network has a documented replacement path.
| Situation | Use | Who you contact |
|---|---|---|
| Lost / stolen / damaged SIM, same network | SIM swap | Current network |
| Wrong SIM size / move to eSIM, same network | SIM swap | Current network |
| Move to a different UK network, keep number | Port (PAC) | Losing + gaining networks |
| First-time go-live of a Create Numbers purchase | Inbound PAC port | Gaining network + Get connected |
Create Numbers does not perform the network SIM swap for you. After your custom number is live on a network, that network’s account tools, app, store or phone channel owns replacement SIMs.
When you need a SIM swap
You need a SIM swap when the credential in the handset fails or must change, but the number and network account should stay put. Typical triggers: cracked or water-damaged nano-SIM, phone theft, upgrade to a handset that needs eSIM, or a failed eSIM download. Ofcom’s lost/stolen guidance also reminds customers they may be liable for charges until the provider is told — and that EE, O2, Vodafone and Three customers who report within 24 hours should typically face a capped unauthorised-use liability (Ofcom summarises a £100 cap outside allowance for those brands when reported in time) (Ofcom lost or stolen).
| Trigger | Priority action | Then |
|---|---|---|
| Lost or stolen handset / SIM | Bar SIM (+ IMEI block if advised) | Order replacement SIM / eSIM |
| Damaged SIM | Order replacement | Activate when it arrives |
| New handset form-factor | Order correct SIM or eSIM | Swap when ready |
| Suspected fraud / SIM-swap attack | Freeze account with network | Reset credentials; review WhatsApp sessions |
How UK networks handle replacement SIMs
Major UK networks let existing customers order a replacement online, in-app, by phone or in store, then activate the new SIM so the old one stops working. Processes differ by brand, but identity checks are increasingly strict because fraudulent “SIM swap attacks” are a known industry risk. Examples of published routes: EE documents account and store replacement including ID checks (EE — SIM swap / new SIM); Vodafone offers order and “swap my SIM” journeys and quotes roughly two to three working days delivery when ordering by phone (Vodafone — Swap your SIM); Three publishes My3 / app “Replace SIM” flows and next-day style delivery windows for many orders (Three — Replacement SIM cards); O2 documents swap/activate help for lost, stolen or size-change cases (O2 — SIMs and numbers).
| Network (examples) | Typical self-serve start | Notes |
|---|---|---|
| EE | Account → eSIM/SIM Replace; or store / 150 | App or physical ID for store fraud checks |
| O2 | Account / help journeys for replacement | Activate before expecting full service |
| Vodafone | 191 / 0333 3040 191; online swap tools | Keep old SIM until new one activates if you still have it |
| Three | My3 or Three app → Replace SIM | Physical or eSIM options |
| MVNOs (giffgaff, Tesco Mobile, VOXI, Smarty, …) | That brand’s app / help | Host radio network may differ — see Network resources |
Never approve a SIM swap you did not request. If your network messages you about a swap you did not start, treat it as urgent fraud and contact them on a number from their official site.
Step-by-step: replace a SIM on your current network
Complete identity checks, order the right SIM type, then activate only when you are ready to cut over — especially if WhatsApp Business or banking OTPs depend on that number. Meta reported WhatsApp at more than 3 billion monthly active users in Q1 2025 remarks (Meta Q1 2025 earnings commentary summarised in press), so losing SMS briefly can lock you out of business chat until the new SIM is live. Sensor Tower reported WhatsApp’s UK app monthly active users above 54 million by March 2025 (Sensor Tower Q1 2025 UK social brands).
- Sign in to your network account (or call / visit using official channels).
- Choose replace SIM / eSIM and the reason (lost, damaged, upgrade).
- Complete any ID or security challenges.
- Wait for the plastic SIM or scan the eSIM QR / install profile.
- Insert or install, then follow the network’s activate / swap step so the old SIM dies.
- Test calls, SMS and mobile data; re-verify apps that bind to the number (WhatsApp verification).
| Checkpoint | Done when… |
|---|---|
| Old SIM barred (if lost/stolen) | Network confirms bar / IMEI steps |
| New SIM in hand or eSIM installed | Profile shows signal |
| Swap activated | Outbound call/SMS works on the custom number |
| Critical apps re-checked | WhatsApp / banking OTP paths tested |
Lost or stolen: bar first, then replace
If the handset or SIM is missing, security first — bar the SIM, consider an IMEI block, then order the replacement so your Create Numbers digits return on a SIM only you control. Ofcom publishes provider contact numbers for lost/stolen reporting and stresses recording your IMEI (dial *#06#) ahead of time (Ofcom lost or stolen). After cutover, review forwarded SMS, voicemail PINs and any virtual hosting sessions if you also use a partner dashboard.
| Order of operations | Why |
|---|---|
| 1. Report lost/stolen to network | Stops spend and misuse |
| 2. Note crime reference if stolen | Insurers / police |
| 3. Order replacement SIM / eSIM | Restores your number |
| 4. Retest business channels | WhatsApp, payments, 2FA |
After the swap: what stays the same
Your mobile number, airtime account and (usually) tariff stay the same; only the SIM credential changes. Create Numbers does not issue a new PAC for a same-network SIM swap. If you instead move to another provider, return to Number porting. Coverage questions after a swap are almost always handset or local signal issues — use Network resources and your network’s coverage checker.
| Stays the same | May change |
|---|---|
| Custom 07 number | SIM ICCID / eSIM profile |
| Network account & number | Temporary SMS downtime during cutover |
| Create Numbers purchase record | Nothing — no repurchase needed |
Frequently Asked Questions
Should I contact Create Numbers to replace a lost SIM?
No — contact the UK network that currently hosts the number. Create Numbers supplied the custom digits (via PAC); the live SIM is the network’s. Re-open Create Numbers only if you never completed inbound porting and still need fulfilment help.
Should I request a new PAC for a SIM swap?
No — PAC is for changing provider (or first inbound go-live). A same-network replacement uses the network’s SIM swap tools. Using a PAC unnecessarily can move you off the account you meant to keep.
Should I choose eSIM or another plastic SIM?
Choose eSIM if your handset and network support it and you want instant download; choose plastic if you need a physical fallback or the network’s eSIM path is blocked. Test WhatsApp and banking SMS on the new profile before you discard the old SIM (when you still have it).
Should I swap SIMs the same day I print new marketing?
Only after a live test on the new SIM. Brief SMS gaps are common during activation. Schedule print runs after inbound SMS works.
Should I worry about SIM-swap fraud on a memorable business number?
Yes — vanity and high-value business lines can be attractive targets. Use network security (strong account passwords, nominated numbers, app approvals) and never share one-time codes. Escalate unexpected swap texts immediately.
Should MVNO customers use EE/O2/Vodafone/Three store processes?
Usually no — use your MVNO’s help channels (for example giffgaff, Tesco Mobile, Lebara), even when radio coverage is supplied by a big MNO. See Network resources for who sits on which host network.
Should I keep the optional Create Numbers PAYG SIM as a spare?
Only if that SIM is still the one hosting the number — a spare inactive card does not carry the digits after you ported away. Once the number lives on a network SIM, that network’s replacement process applies. Store old cards securely or destroy them after a successful swap.
Should I notify WhatsApp before swapping?
You do not notify Meta in advance for a routine SIM swap, but you should be ready to re-verify if the app challenges the device. Keep another login route to business assets where possible. See WhatsApp verification.
Should I delay a handset upgrade until after month-end billing?
Not required for the swap itself — billing stays on the same account. Delay only if you need uninterrupted OTP SMS during a critical payroll or launch window. Perform the cutover in a quiet hour and test immediately.
Should I open a brand-new network account instead of swapping?
Only if you intend to leave the old account — that path needs a PAC into the new account, not a SIM swap. Compare total cost (ETCs vs simplicity) before you choose. Porting steps: Number porting.