Keeping Your Number When You Change Carriers
A telephone number is not owned by the subscriber and not owned by the carrier, which is why the rules governing its movement are procedural rather than proprietary. Almost every failed port is a mismatch in four small fields.
What this report covers
- Porting is initiated with the new carrier while the old account remains open.
- A losing carrier may not refuse a port because a balance is outstanding or a term is unexpired.
- Simple wireless ports are subject to a short mandated completion interval.
- Most rejections arise from a mismatch in name, service address, account number or passcode.
- Geographic limits apply: a landline number can generally only move within its rate center.
- Carriers must authenticate the customer before releasing a number to protect against fraudulent transfer.
Number portability was imposed to remove a barrier to competition: so long as changing carrier meant changing number, most customers would not change carrier. The result is a system in which the number is administered rather than owned, and the subscriber's right is a right to have it moved on request.
How a port actually runs
The request always originates with the carrier being joined, never with the one being left. A customer who calls the existing carrier to cancel has performed the opposite of a port, and once the account closes the number returns to the numbering pool.
- The customer gives the new carrier the number, the account details and any transfer passcode.
- The new carrier submits a port request to the losing carrier through the industry system.
- The losing carrier validates the request against its records and either concurs or rejects it.
- On concurrence, routing is updated so calls to the number reach the new network.
- The old account closes for that number, and a final bill issues including any outstanding charges.
The validation step is where everything fails. The losing carrier may only check a limited set of fields, and it must find an exact match. Discrepancies in the service address, the account number format, the spelling of the subscriber name, or a passcode the customer never knowingly set will each produce a rejection, usually with a code the receiving carrier does not translate for the customer.
Porting requires the losing account to be active. A canceled number is released, and although a short recovery window sometimes exists as a courtesy, there is no entitlement to get it back once it has been returned to the pool.
What a losing carrier may and may not refuse
| Ground for refusal | Permitted | Why |
|---|---|---|
| Unpaid balance on the account | No | The debt survives the port and is collected separately |
| Unexpired term commitment | No | Early termination charges apply but do not block release |
| Details do not match the record | Yes | Validation is required to prevent fraudulent transfer |
| Number outside the receiving carrier's coverage | Yes, for wireline | Geographic numbering limits apply to fixed numbers |
| Number not assigned to the requesting subscriber | Yes | Authorization is a precondition |
| Account already subject to a pending port | Yes, temporarily | Only one request may be in flight |
Geography deserves its own note because it defeats moves that customers assume are routine. A traditional landline number belongs to a rate center, and it can generally only be ported to a carrier serving that rate center. Moving house across a metropolitan area can therefore make a number unportable to a fixed line even though it would port to a wireless or internet-based service without difficulty. Wireless numbers travel far more freely, and internet-based voice services will usually accept a number from anywhere they hold interconnection.
Timing, and the interval that is mandated
Simple wireless ports are subject to a short mandated completion interval measured in hours once the request is validated, and customers should expect same-day movement in ordinary cases. Wireline and business ports take longer because they may involve physical facilities, multiple numbers or complex service arrangements, and the intervals negotiated in those cases are correspondingly longer.
Two practical points about the transition. Service on the old carrier ends for that number at the moment routing changes, so anything depending on it — two-factor codes, alarm monitoring, a fax line — should be identified beforehand. And a port completed mid-cycle does not usually generate a refund of the month already billed, which is one of several charges that appear on a final statement and are argued about afterwards.
Protecting the number from being taken
Because a number can be moved by record change alone, control of the number is a security question. Carriers are required to authenticate a customer before transferring a number to another provider or moving service to a new device, and to notify the account holder promptly when such a request is made. Those requirements exist because the transfer is a favored route into accounts protected by text message verification.
The protective measures worth taking are unglamorous: set a transfer passcode distinct from every other credential, enable any port-out lock the carrier offers, keep the account contact details current so notifications actually arrive, and treat a sudden unexplained loss of service as an emergency rather than a fault. The campaigns that harvest the information needed to impersonate a subscriber are the same ones described in the enforcement architecture built around spoofed and automated calls.
Where a carrier refuses a port outright, conditions it on payment, or fails to act within the interval, the remedy is a federal informal complaint, which obliges a written response. That is the same channel used for disputes over disclosed service terms and charges, and it does not run through a state utility commission, which has no general authority over wireless service.
Sources
- Cornell Legal Information Institute — 47 U.S.C. 251, Interconnection and Number Portability
The statutory duty of carriers to provide number portability.
- eCFR — 47 CFR Part 52, Numbering
The rules governing number administration and portability obligations.
- Federal Communications Commission — Porting: Keeping Your Phone Number
Consumer guidance on how a port is initiated and what carriers may require.
- Federal Communications Commission — Cell Phone Fraud
Unauthorized transfer of a number or a device, and the protections against it.
- Cornell Legal Information Institute — 47 U.S.C. 222, Customer Proprietary Network Information
The confidentiality duty underlying carrier authentication requirements.
- Federal Communications Commission — Filing an Informal Complaint
The route for complaints where a carrier refuses or delays a port.
Questions readers ask
Can my carrier hold my number until I pay what I owe?
No. A losing carrier may not refuse or delay a port because a balance is unpaid or a term commitment is unexpired. The debt survives the port and remains collectable, including any early termination charge, but it is not a lawful ground to keep the number. If a carrier conditions release on payment, say that the refusal is not permitted, escalate within the carrier, and file a federal informal complaint if it persists.
Why do porting requests keep getting rejected?
Because the details submitted must match the losing carrier's records exactly, and customers supply what they believe rather than what is recorded. The usual culprits are a service address that differs from the billing address, an account number formatted differently from the one on the bill, a name recorded with a middle initial, and a transfer passcode the customer never set. Take the details from a recent bill rather than from memory.
What stops someone else porting my number away?
Carriers are required to authenticate a customer before transferring a number or moving service to a new device, and must notify you promptly when such a request is made. Set a distinct transfer passcode that differs from any other credential on the account, treat an unexpected notification as urgent, and contact the carrier immediately if service drops without explanation, which is often the first sign of an unauthorized transfer.
