Porting moves your existing phone numbers from your current carrier to a new one, so you keep the numbers your customers already know. It runs on a signed authorization and account details that must match your current carrier's records exactly, and most business ports take 2–4 weeks from submission to completion. The single most important rule: do not cancel your old service until the port has finished.
Most ports go through without drama. The ones that do not usually fail for boring reasons, such as a misspelled company name, an old service address or a number nobody knew was on the account. Almost all of that can be avoided before you submit.
How porting works
In the US, local number portability rules let businesses keep their numbers when they change providers, within the limits of what the new provider can serve. Your new provider, not you, starts the process:
- Portability check. The new provider confirms it can serve each number. Numbers belong to rate centres, and a provider has to be able to take numbers from that area.
- Authorization. You sign a letter of authorization (LOA) naming the numbers and your account details.
- Submission. The new provider sends the port request to your current carrier.
- Validation. Your current carrier checks the request against its records. If anything does not match, it rejects the request and the clock restarts once it is fixed.
- FOC date. Once accepted, your current carrier issues a firm order commitment, the date and often the time the numbers will move.
- Cutover. On that date, the numbers are re-pointed to the new provider. Calls start arriving on the new system.
Under FCC rules, your current carrier may not refuse a valid port because you still owe it money or are under contract. Those obligations do not disappear, though: an early termination fee or final balance is still due under your contract.
What you need before you submit
- A recent bill from the current carrier, all pages.
- The customer service record (CSR) if you can get it. It is the carrier's own record of your account, and it is what your request will be checked against.
- Account number, exactly as the carrier has it. Some carriers use a different number for porting than the one on the bill.
- Billing telephone number (BTN), the main number the account is filed under.
- Authorized name and business name, spelled the way the carrier spells them.
- Service address as the carrier has it, which may be an old address if you have moved.
- Port-out PIN or passcode, required by mobile carriers and many VoIP providers.
- A complete list of numbers, including direct-dial ranges, fax lines and anything else on the account.
Why ports get rejected
| Rejection reason | What it usually means | The fix |
|---|---|---|
| Name mismatch | The LOA says "Smith & Co LLC," the carrier has "Smith and Company" | Copy the name from the CSR, character for character |
| Address mismatch | The account still shows your old office, or a different suite | Use the address on record, not your current one |
| Wrong account number or PIN | The bill number is not the porting account number, or the PIN is missing | Ask the current carrier for the porting account number and PIN |
| BTN issue | You are porting some numbers but not the main one, without saying what happens to it | Specify a partial port, and which number becomes the new BTN |
| Number not on account | A number sits on a different account, or was never yours | Split the request by account; confirm ownership |
| Pending order | An open change or move order on the old account blocks the port | Close or cancel the pending order first |
Full, partial and special cases
Full vs partial ports
A full port moves every number on the account, and the old account usually closes as a result. A partial port moves some numbers and leaves others. If you port the BTN but not everything else, the old carrier needs a new BTN for the remaining service. Say clearly which numbers stay.
Toll-free numbers
Toll-free numbers do not port through the local process. They move by changing the responsible organisation (RespOrg) that manages them. Ask your new provider whether it handles this and allow for separate timing.
Mobile numbers
Mobile numbers can often be ported to a business voice platform. They need the mobile carrier's account number and port-out PIN, and once ported the number no longer works for calls on that mobile plan.
Lines that are not really phones
Before any port, check what is physically on the old lines. Fax machines, alarm panels, elevator phones, card terminals and some internet services ride on phone lines. Porting a number that DSL internet rides on, for example, can take the internet down with it. Plan each one: move it, replace it, or leave it where it is on purpose.
Realistic timelines
The FCC requires simple ports to complete within one business day, but "simple" has a narrow definition, roughly a single line with no complex services attached. Most business ports are not simple: multiple numbers, direct-dial ranges, several accounts or a PBX. Those typically take 2–4 weeks from a clean submission. A rejection resets the clock, which is why getting the details right the first time matters more than anything else.
A worked example
A hypothetical office, with invented numbers of lines and dates, to show how a port is planned.
Suppose a 30-person office is moving to a new phone system. It has 32 numbers across two accounts with the same carrier:
- Account 1: the main number (the BTN), 25 direct-dial numbers and 3 fax lines.
- Account 2: an alarm line and an elevator line, set up years ago by the landlord's contractor.
- Separately, a toll-free number managed by another company.
The plan: port all 29 numbers on Account 1 in one request. Leave Account 2 alone, because the alarm and elevator lines need their own solution and the landlord has to be involved. Move the toll-free number with a RespOrg change as a separate task. Move two of the fax numbers to a fax-to-email service on the new platform and retire the third.
| Day (hypothetical) | Step |
|---|---|
| Day 1 | Pull the CSR, confirm name, address, account number and PIN |
| Day 2 | Portability check done; LOA signed; request submitted |
| Days 3–7 | Current carrier validates; one rejection for a suite number, corrected and resubmitted |
| Day 9 | FOC received for a Wednesday morning two weeks later |
| Days 10–22 | New phones installed and tested on temporary numbers; call flows built |
| Day 23 | Cutover; test calls from mobiles to every main number and a sample of direct lines |
| Day 24 on | Confirm Account 1 closes; review the final bill |
The one corrected rejection is realistic. Allowing for one is how you keep a move-in date safe.
A cutover-day plan
- Pick a mid-week morning, so both carriers' support teams are working and you have the day to fix issues.
- Have the new system fully built and tested on temporary numbers before the day.
- Test inbound calls from outside, from mobiles on different networks, to the main line, direct numbers and fax.
- Test outbound caller ID, so your number displays correctly.
- Check 911 locations are set on the new system for every phone. See E911 rules for business phones.
- Keep the old system connected until calls are confirmed arriving on the new one. Different carriers update at slightly different speeds for a short period.
After the port
A full port usually closes the ported services, but not always everything on the account. Check for leftover services, such as an internet line, a leftover channel or equipment rental, and cancel what you no longer need in writing. Watch the next bill or two for charges after the port date. If you are moving office at the same time, the office move checklist covers the rest of the timing.
Protecting your numbers
Numbers can be ported away fraudulently, and business mobile lines are a common target. Set a port-out PIN or port freeze on every account that supports one, keep it somewhere only authorised staff can reach, and ask your providers to flag any port request on your account.
Questions to ask your new provider
- Who submits and manages the port, and who do I call if it is rejected?
- Can you port every number on my list, including toll-free and any mobiles?
- Do you need the CSR, and will you help me get it?
- Can I choose the cutover date and time of day?
- Can the new system run on temporary numbers for testing before the port?
- What happens if the port completes but calls do not arrive?
Getting your numbers moved safely
We manage number ports as part of every business voice and hosted phone order, including gathering the records and chasing the current carrier, and we compare providers for you in the same quote. If you are still choosing a system, start with SIP trunking vs hosted PBX. The quote is free with no obligation, and you usually hear back the same day. Send us a recent phone bill, call 478-758-8091 or text (347) 870-0965.
