Bringing your existing number with you.

What porting is

Number portability is the right to keep your telephone number when you change providers. It exists because a business number is not really a technical identifier; it is an asset printed on vans, invoices, signage and every directory listing you have ever been in. Being forced to give it up to change supplier would lock every business to its first carrier forever.

Mechanically, your new provider submits a request to your current one. The current provider validates that the request matches its own records, agrees a date, and on that date the number's routing is changed. Your old line keeps carrying calls throughout, so there is no window where your number is dead.

This page covers the process and the rules. If what you want is the timeline itself — how long each kind of port takes, across the US, Canada, the UK and Australia — that is the subject of our long-form article, how long does it take to port a phone number.

The US rules, stated precisely

United States The intervals are set by 47 CFR § 52.35 and they are narrower than most summaries suggest.

A carrier "must complete a simple wireline-to-wireline or simple intermodal port request within one business day unless a longer period is requested".1 A non-simple request gets four business days,1 and carriers holding a waiver also get four.1

"Intermodal" is defined in the rule as wireline-to-wireless ports, wireless-to-wireline ports, and "Ports involving interconnected VoIP service".1

Two details in the rule catch people out. There is a daily cutoff: "An accurate and complete Local Service Request (LSR) must be received by the current service provider between 8 a.m. and 1 p.m. local time", and anything later "will be considered received on the following business day at 8 a.m. local time".1 A request submitted at 2pm has not started yet. And "business day" is defined as "Monday through Friday" with "8 a.m. to 5 p.m." as minimum business hours,1 so a Friday afternoon submission realistically moves on Monday.

What makes a port "simple"

This determines whether you wait one business day or four, and there is a genuine surprise here: the Code of Federal Regulations does not define "simple port" anywhere. The term appears in the operative text of §§ 52.35 and 52.36 but in no definitional paragraph.7

The nearest thing to an authoritative description is the FCC's own consumer guidance: "FCC rules require simple ports, which generally do not involve more than one line or more complex adjustments to telephone switching equipment, to be processed in one business day."3

The four-prong industry formulation you will see quoted on vendor sites — no unbundled network elements, a single line, no complex switch translations, no reseller — may well be accurate, but we could not locate it in the CFR or in the Federal Register notices we were able to read,6 so we are not presenting it as regulatory text.

What is fixed in the rule is the data. Section 52.36 states that "A telecommunications carrier may require only the data described in paragraphs (b) and (c) of this section to accomplish a simple port order request".2 There are fourteen fields, and the ones you personally need to supply are few: the ported telephone number, the account number, the zip code, and the desired due date.2 A passcode is optional "unless the passcode has been requested and assigned by the end user".2

That list is a useful piece of leverage. If a carrier demands something outside it to process a simple port, the rule says they may require only those fields.

Why ports get rejected

Nearly every rejection is a mismatch between what your new provider submitted and what your old provider has on file. The old record is often years out of date and reflects whoever originally opened the account.

• Account number wrong or absent. It is on the bill, and it is not your phone number. This is the single most common cause.
• Name mismatch. The account may be in a trading name, a previous company name, or a former owner's personal name. Submit it exactly as the old carrier holds it, not as you would write it today.
• Service address mismatch. Including the zip code, which is one of the fourteen fields.2 If you have moved and never updated the carrier, their address is the one that must be used.
• Missing or wrong transfer PIN or passcode where the carrier has assigned one.2
• A port-out freeze on the account, which some carriers apply by default as an anti-fraud measure and which only you can lift.
• Pending changes on the account. A port request submitted while another order is open will usually bounce.
• Partial ports of a multi-line account, which are generally not simple and take the longer interval.1

Get a recent bill in front of you before starting and copy the details from it character for character. That one step removes most rejections.

The mistake that is not recoverable

The corollary is that you should expect a period of overlap and a final bill from the old provider. That is normal and it is the cheap end of this trade.

Money, debts and fees

United States Two rules here are worth knowing because carriers do not always volunteer them.

An unpaid balance cannot block your port. "Once you request service from a new company, your old company cannot refuse to port your number, even if you owe money for an outstanding balance or termination fee."3 The debt survives — you still owe it — but it is not leverage over your number.

Porting itself may carry a fee. "Companies may charge you to port your number, but you can ask whether any fees can be waived or negotiated."3 Check your contract for early termination charges before you start, since those "you are obligated to pay".3

Toll-free numbers work completely differently

A toll-free number is not ported in the sense above. It is administered through a central database, and moving it means changing which organisation controls its record.

That organisation is a RespOrg, defined in 47 CFR § 52.101 as "The entity chosen by a toll free subscriber to manage and administer the appropriate records in the toll free Service Management System for the toll free subscriber."4 The database itself "enables Responsible Organizations to enter and amend the data about toll free numbers within their control",4 and is run by a Toll Free Numbering Administrator appointed by the Commission.4

The FCC's guidance confirms the practical position: "Somos, Inc., administrator of the toll free number database, certifies RespOrgs", and "The FCC requires that toll free numbers be portable, meaning that a subscriber can 'port,' or move, their number to a new RespOrg when changing service providers."5 Current toll-free codes are "800, 888, 877, 866, 855, 844 and 833."5

Importantly, the § 52.35 intervals do not apply here — Subpart D, which governs toll-free numbers, contains no equivalent porting-interval rule. Anyone quoting you a one-business-day toll-free port is quoting a commercial commitment, not a regulation.

A pre-port checklist

1. Find a recent bill from the current provider. Everything you need is on it.
2. Copy the account holder name and service address exactly as the carrier has them, not as they should be.
3. Locate the account number, and request a transfer PIN if the carrier uses one.
4. Check for a port-out freeze and lift it.
5. Check the contract for early termination fees so there are no surprises.
6. Submit early in the day. In the US, requests after 1pm local time count as next business day.1
7. Pick a due date that is not a Friday, unless you want any hiccup to sit over the weekend.
8. Do not cancel the old service. Wait for confirmation that the port has completed, then cancel.3

Outside the United States

Every interval on this page is United States federal law and none of it transfers. The UK operates a PAC-code based process regulated by Ofcom, and Canada's is set through the CRTC, each with its own timescales and mechanisms.

We attempted to verify the current UK and Canadian figures against the regulators' own sites for this page and could not retrieve them. Rather than repeat numbers we have not read at source, we are leaving them out. If you are porting in either country, check the regulator directly — and be sceptical of any page that states a global porting time, because there is no such thing.