Number porting follows the same underlying sequence in every country: obtain a transfer credential from your current carrier, provide it to your new carrier, and wait for the port to complete. The differences lie in what that credential is called and how you obtain it — and in whether you need to contact your old carrier at all.
This guide walks through the complete port process step by step, with the exact credential and method for the UK, US, France, Australia, and Japan. It then covers what happens on the day of cutover and how to confirm the port is complete.
For a technical explanation of how number portability databases and call routing work, see Mobile Number Portability (MNP) Explained.
The Universal Port Sequence
Every country with mandated number portability follows the same five-stage process. What varies is the credential name and who contacts whom.
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Gather your account details. Before doing anything else, collect your account number with the current carrier and the exact registered name and billing address on the account. A mismatch at any point causes the port to be rejected.
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Obtain a transfer credential from your current carrier — or authorise your new carrier to request it on your behalf. The credential type and how you get it differs by country; each is described in the sections below.
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Sign up with your new carrier and provide the credential. The new carrier submits a port-in request to the national number portability database. At this point, the clock starts on the regulatory completion window.
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Wait for the cutover. Your old SIM loses service first. A few minutes to a couple of hours later, your new SIM acquires signal with the ported number.
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Verify the port is complete. Make a test call and send a test SMS before treating the switch as finished.
Before completing step 1, confirm that your device is SIM-unlocked — a successful port on a locked device leaves you with a working number but no usable service. For how to check, see SIM Lock and SIM-Free Explained.
Step 1 — Gather Your Account Information
The information you need varies slightly by country, but most port-in forms ask for the same core set:
| Field | Where to find it |
|---|---|
| Phone number to port | Your own number |
| Account number | Billing statement or carrier account portal |
| Registered name | Account portal — copy the name character for character |
| Billing address | Account portal or latest bill |
| Transfer credential | Varies by country — see below |
The account number is an internal identifier, not your phone number. It is on your bill or visible in your carrier’s online account portal after login.
Name matching is critical. A difference of one character — a hyphen, a middle initial, “Jr.” appended or missing — is sufficient to cause a rejection. Before submitting the port request, log in to your current carrier’s portal and screenshot the exact name as displayed. Use that spelling when filling in the new carrier’s form.
If your line is on a family or shared plan, confirm whether you are listed as the primary account holder. In most markets, a port request must be authorised by the account holder. If you are not the account holder, the holder may need to provide the transfer credential or authorise the transfer on your behalf.
Step 2 — Obtain Your Transfer Credential
This is the step that differs most by country.
United Kingdom — PAC Code (text 65075)
Text PAC to 65075 from the number you want to port. Ofcom rules require your current carrier to send the Porting Authorisation Code (PAC) within 60 seconds, free of charge. The PAC is valid for 30 days.
If you want to leave your carrier without keeping your number, text STAC to 75075 instead. This returns a Service Termination Authorisation Code.
Give the PAC to your new carrier. Ofcom rules require the port to complete within one working day of the new carrier receiving a valid PAC.
Source: Ofcom: Switching — mobile
United States — Number Transfer PIN
In the US, porting is governed by the FCC’s Local Number Portability (LNP) mandate. To port your number, you need:
- Your account number with the current carrier.
- A Number Transfer PIN — a code that is distinct from your account login password, billing PIN, or SIM card PIN.
Most US carriers now require customers to set up a Number Transfer PIN in their account portal or app. If you have not set one, do this before contacting the new carrier. The new carrier submits the port request using the account number and transfer PIN together.
The FCC mandates that simple ports be processed within one business day.
Source: FCC: Porting — Keeping Your Phone Number When You Change Providers
France — RIO Code (call 3179)
Call 3179 from the mobile number you want to port. The call is free of charge and available 24 hours a day, seven days a week. An automated message reads out your RIO (Relevé d’Identité Opérateur) code. The RIO remains valid while your contract is active.
Provide the RIO to your new carrier when signing up. The gaining carrier submits the port request. Under ARCEP Decision No. 2022-2148, simple prepaid ports must complete within one working day; postpaid ports may take up to three working days.
Porting is free of charge in France.
Australia — Gaining-Carrier Model
In Australia, you do not need to contact your current carrier or obtain a transfer code. The gaining carrier handles the entire port-out process on your behalf.
When you sign up with the new carrier, they will ask you to authorise the transfer and will verify your identity before proceeding. This identity verification step — which may include an SMS OTP sent to the number being ported or another approved verification method — was introduced by the Telecommunications (Mobile Number Pre-Porting Additional Identity Verification) Industry Standard 2020 to combat port-out fraud.
ACMA industry service levels require 90% of simple mobile ports to complete within three hours. Porting is free.
Source: ACMA: Keep or transfer your phone number
Japan — One-Stop MNP and Reservation Number
Japan operates two parallel methods.
One-Stop MNP (since May 24, 2023): Complete the entire transfer on the new carrier’s website without contacting the old carrier at all. This method is available online only and for eligible carrier combinations. The new carrier requests the transfer directly from the current carrier’s system.
Traditional MNP: Obtain an MNP reservation number (MNP予約番号) from your current carrier — by phone, app, or in-store. The reservation number is valid for 15 days. Provide it when signing up with the new carrier.
Source: MIC Japan — One-Stop MNP
Other Markets
In Germany, the gaining carrier initiates the port request on your behalf under §59 TKG; you do not need a separate code, though the carrier will verify your identity. In Canada, you provide your account number and transfer PIN to the new carrier, which submits the port under CRTC number-portability rules (Telecom Decision CRTC 2005-72); simple wireless ports must complete within 2.5 hours.
EU member states generally follow one of two models: a customer-obtained code (similar to the UK or France) or a gaining-carrier-initiates model (similar to Australia or Germany). Within the EU, the European Electronic Communications Code (Directive 2018/1972) requires that porting complete within one working day and be free of charge. Individual member states determine the specific credential mechanism.
Step 3 — Sign Up with Your New Carrier
During the sign-up flow, your new carrier will ask for the account details you gathered in step 1 and the transfer credential from step 2.
Timing matters here. Do not sign up with the new carrier and activate your new SIM or eSIM before you have the transfer credential in hand. Activating the new SIM without a port request means the SIM gets a new number, and any subsequent port request has to start from scratch.
When filling in the sign-up form:
- Use the registered name exactly as it appears on your current carrier’s account.
- Use the account number, not your phone number, in the account number field.
- Enter the transfer credential (PAC, Number Transfer PIN, RIO, or equivalent) exactly as received.
Once the new carrier submits the port request, you will typically receive a confirmation — by email or SMS to a secondary number — with an estimated completion time.
While selecting a new carrier, compare current plans using SimFinder — plans change frequently, so check current offers before committing.
Step 4 — Wait for the Cutover
After the port request is submitted, the number moves through a technical process: the current carrier updates its porting database record, routing tables propagate across networks, and the new carrier’s switch activates the number on its infrastructure.
During this window, which typically lasts from a few minutes to a few hours depending on the country:
- Your old SIM will lose service first. This is normal.
- SMS messages may not be reliably delivered to either SIM.
- Calls to your number may fail intermittently.
Do not trigger any SMS-based two-factor authentication logins during this period. If you need to log in to a banking, email, or work account during the port window, use an authenticator app or a backup code instead of waiting for an SMS code. For a full explanation of how to prepare for this, see Pre-Switch Checklist.
Do not cancel your current account. In most markets, the current carrier automatically closes the account when the port completes. If you cancel manually before the port is done, your number returns to the carrier’s number pool and may be impossible to recover.
If you are porting to an eSIM: Some platforms prompt you to download and activate the eSIM profile during the sign-up flow, before the port-out from the old carrier completes. Do not activate the eSIM profile until your new carrier explicitly confirms the port is complete. Activating early can create a state where the eSIM has network access but the ported number is not yet routed to it. Wait for the confirmation, then tap activate.
Step 5 — Day-of Cutover Verification
When the port completes, your new SIM will show network signal and your ported number will be active on the new carrier.
Verify the port is complete before discarding the old SIM:
- Make a test call. Call a known number — a friend, a voicemail service, or a secondary line — and confirm it connects through the new carrier.
- Send a test SMS. Send a message to yourself from another device, or ask a contact to send one. Confirm it arrives.
- Check mobile data. Open a website that does not use cached content to confirm data connectivity on the new plan.
- Confirm your number is displayed correctly. Some devices take a few minutes to refresh the displayed number in Settings after a port.
If the new SIM shows signal but calls fail, the routing update may still be propagating. Wait 15–30 minutes before concluding there is a problem.
If the port has not completed within the regulatory window for your country — one working day in the UK and most EU markets, 2.5 hours in Canada, three hours for 90% of Australian simple ports — contact your new carrier’s support first. They can check the port request status and identify whether it was rejected. If neither carrier resolves the issue within the regulatory window, contact the relevant authority: Ofcom (UK), FCC (US), ACMA (Australia), ARCEP (France), or Bundesnetzagentur (Germany).
What Cannot Be Ported
Number portability transfers one thing only: the phone number. Nothing else moves between carriers automatically.
| What moves | What does not move |
|---|---|
| Your phone number | Voicemail messages |
| — | Call logs and SMS history |
| — | Carrier app loyalty points or credits |
| — | Carrier email addresses |
| — | Promotional data credits or roaming packages |
| — | Any data stored on the old carrier’s servers |
Voicemail: Messages stored on your old carrier’s voicemail servers remain accessible only through the old carrier’s system, for a limited time after the account closes. Listen to and note any important voicemails before the port begins. If you use visual voicemail, take screenshots or notes of any messages you need to keep.
Carrier email: Addresses in a carrier’s domain stop working when the account closes. This is a separate issue from number portability. Switch to a provider-independent address before the switch and update every service that uses your carrier address.
Numbers between countries: MNP is a national framework. A number cannot be ported from one country to another. If you need to maintain a number from one country while using a carrier in another, a VoIP number or dual-SIM setup is the available workaround — not porting.
Common Port Rejection Reasons
Most failed ports fall into one of four categories:
Name or address mismatch. The name submitted to the losing carrier does not exactly match the account. Check character for character — a hyphen, a middle initial, or abbreviated company name is enough to cause rejection.
Wrong credential type. Providing an account login password, billing PIN, or SIM card PIN instead of the specific Number Transfer PIN (US) or PAC code (UK). These are different. Request the specific transfer credential before starting the port.
Account lock. In the US, carriers offer voluntary account locking features (such as Verizon’s Number Lock or AT&T’s Wireless Account Lock, introduced in 2025) as fraud prevention. If you have enabled such a lock, disable it in your carrier’s app before requesting a port. Some carriers also apply a temporary hold after a recent SIM swap or account modification.
Inactive or closed account. A prepaid account with a zero or very low balance may have expired, making it ineligible to port. Top up to confirm the account is active before submitting the port request.
If your port is rejected, the new carrier is required to notify you of the reason. Fix the specific issue — do not start over from scratch — and resubmit. The process restarts from step 3, not step 1.
Checklist Summary
Use this before the day of the switch:
- Account number with current carrier located
- Registered name on account confirmed — exact spelling noted
- Billing address on account confirmed
- Transfer credential obtained or method confirmed (PAC / Number Transfer PIN / RIO / gaining-carrier model / one-stop)
- Device SIM-unlock status confirmed
- SMS 2FA services identified — logged in or authenticator app configured
- Voicemail messages noted or saved
- Carrier email address migration planned
- Contract end date and ETF confirmed
- Device installment balance confirmed
For full preparation detail on each of these items, see Pre-Switch Checklist.
FAQ
(See structured FAQ items in the frontmatter above for display in site search and rich results.)
What if my old carrier refuses to give me a PAC or transfer code?
In the UK, Ofcom rules require carriers to deliver a PAC within 60 seconds of texting 65075 — refusal or delay is a regulatory violation. In France, the 3179 service is mandated by ARCEP. In the US, the FCC prohibits carriers from refusing or delaying a port based on an outstanding balance. If your carrier fails to provide the credential or stalls the process without a valid reason, file a complaint with the relevant national regulator.
My port completed but my phone shows the old network name. Is that a problem?
No — this is typically a display cache issue. Restart the device, or toggle Airplane Mode off and on. If the problem persists after 30 minutes, go to Settings and manually select your new carrier’s network. Confirm that the correct network name appears in the carrier settings on your new SIM’s account page.
Can I port a number that is currently on a prepaid account?
Yes — prepaid number portability is mandated in the same countries as postpaid. The process is identical. The one practical difference: ensure your prepaid account is active (not expired due to zero balance) before initiating the port. An expired prepaid number may have already been released back to the carrier’s pool.
How do I check which carrier to switch to before porting?
Choosing a new carrier involves comparing coverage, data allocation, contract terms, and pricing. Use SimFinder to compare current plans, and How to Choose a Travel eSIM: 5 Key Criteria for a framework covering the factors that matter most. For a side-by-side breakdown of plan structures across providers, see Travel eSIM Provider Comparison.
Related Guides
- Mobile Number Portability (MNP) Explained — Technical background on how porting databases and call routing work, plus country-by-country timing tables.
- Pre-Switch Checklist — Full preparation checklist: SIM lock, 2FA migration, ETF, voicemail, carrier email, and device backup.
- SIM Lock and SIM-Free Explained — How to confirm your device is unlocked before the port, and how carrier unlock policies work by region.
- How to Choose a Travel eSIM: 5 Key Criteria — Framework for evaluating a new carrier before you commit to switching.
- Travel eSIM Provider Comparison — Side-by-side comparison of major plan providers for those switching to a global or travel plan.