Can I keep my business phone number when switching to VoIP?

Yes. FCC number portability rules let you keep your number when you change providers in the same area, as long as the account is active and in good standing. Local, toll-free and most mobile numbers can all move to a VoIP provider.

Will my phones go down during the port?

Usually not. The old carrier keeps handling calls right up to the switch at the FOC time. There can be a short window where some calls route to the old carrier and some to the new provider. Scheduling the port outside business hours keeps that risk low.

Can my current carrier refuse to port my number?

Not over money. Under FCC rules a carrier cannot hold your number because of an unpaid balance or an early-termination fee — though you still owe both. It can reject a request for mismatched account details or a missing PIN. Fix whatever reason it gives and resubmit.

Does porting cost anything?

It depends on the provider. Some charge a per-number porting fee, and your old carrier may bill an early-termination fee under your contract. DialPhone charges nothing to port numbers in, on every plan, including toll-free.

How long does a business port take?

DialPhone publishes 5–14 business days for most business ports, and that matches the typical range for several local numbers moving from one carrier. A single line can be quicker, and toll-free, partial ports and legacy PBX lines run longer. The losing carrier’s queue sets the pace.

Can I port only some of my numbers?

Yes, with a partial port. Expect it to take longer than a full port. Check first whether the billing telephone number is one of the numbers moving. If it is, the old carrier needs a new BTN assigned before the request will go through.

How to Port a Business Phone Number (No Downtime, 2026)

Most number ports do not fail on port day. They fail two weeks earlier, when someone types the service address the way it appears on the company website instead of the way it appears on the old carrier’s records.

That one mismatch sends the request back, the clock resets, and the switch slips another week. The part of porting that decides whether it goes smoothly is the paperwork, and the paperwork is entirely within your control.

This guide covers the documents to collect, the eight steps in order, the timelines to expect by number type, and the after-port cleanup most guides skip.

What you need before you start

Collect these before you contact a new provider. Missing any one of them is the fastest route to a rejected port.

A recent bill: From your current carrier, dated within the last 30 days. Include every page that shows the numbers being moved.
Account number and port-out PIN: The PIN applies to wireless lines and is separate from your account password. Major mobile carriers now require one.
The authorized user’s name: Spelled exactly as the carrier has it. “Acme LLC” and “Acme Holdings LLC” are different names to a validation system.
The service address on file: Not always your office address, and not always what is printed on the bill. This is the single most common mismatch.
Every number on the account: Main line, direct-dial numbers, fax, toll-free, and anything wired to an alarm or a lift. The fax line is the one people forget.

Checklist headed "Before you port: what you need" showing five items - a recent bill within 30 days, the account number and port-out PIN, the authorized user name, the service address on file, and the full list of numbers. — Five things. A port that stalls is almost always missing one of them.

Start with the Customer Service Record

Ask your current carrier for the CSR — the carrier’s own internal record of your account. This matters more than any other step, because your port request is validated against the CSR. Not against your bill, and not against what is on your website.

Why the CSR beats the bill: A bill usually shows the billing address. The CSR holds the service address, and porting validation checks the CSR fields. Where the two differ, the losing carrier can reject the request outright.
What to check, line by line: The authorized name, the service address down to the suite number, the account number, and the billing telephone number (BTN). Copy them exactly — including abbreviations and any typo the carrier has on file.

The eight steps, in order

Every port runs through the same sequence. Steps one and two are where the time is won or lost.

Pull the CSRGet the Customer Service Record from your current carrier and check it field by field, as above.
Inventory the numbersList every number on the account, then decide between a full port, which moves everything and closes the account, and a partial port, which leaves some numbers behind and takes longer to process. In a partial port, if the BTN is one of the numbers moving, the old carrier has to assign a new BTN first — sort that out before you submit anything.
Set up the new providerSign up and configure everything before the numbers arrive: users, routing, IVR menus, voicemail greetings, business hours.What the phone system includes
Sign the LOAThe Letter of Authorization is what lets the new provider request the numbers on your behalf, and every field on it should match the CSR exactly. Attach a recent bill.
Submit and wait for the FOCYour provider sends the request. Once the losing carrier accepts it you get a Firm Order Commitment date — the confirmed day and time the numbers actually switch. Do not cancel the old service before then.
Test on port dayFrom a phone outside your own network, so you see what a customer sees.
Update E911 and textingPorting moves the number, not everything attached to it. Both need doing the same day.
Close the old accountConfirm in writing that it is closed, ask for the final bill, and check for early-termination fees or equipment leases still running.

The eight porting steps as a numbered flow: pull CSR, inventory numbers, set up new provider, sign LOA, submit and wait for FOC, test on port day, update E911 and texting, close old account. — The whole sequence. Only step six happens on port day itself.

How long does porting take?

It depends almost entirely on what you are moving and how busy the losing carrier is. The new provider does not set the pace.

Number type	Typical timeline	What slows it down
Single local line	1–5 business days	CSR mismatches, late-day submission
Multiple local numbers, one carrier	5–14 business days	Missing DIDs, BTN questions
Toll-free numbers	1–4 weeks	The RespOrg change through the toll-free registry
Partial ports, legacy PBX, Centrex or ISDN	2–4 weeks	Manual work at the losing carrier
Wireless numbers	1–3 business days	Wrong or expired port-out PIN

Five cards comparing porting timelines: single local line 1 to 5 business days, multiple local numbers 5 to 14 business days, toll-free numbers 1 to 4 weeks, partial port or legacy PBX 2 to 4 weeks, and wireless numbers 1 to 3 business days. — DialPhone publishes 5–14 business days for most business ports, which lines up with the second column.

Testing on port day

The switch happens during a set window on the FOC date. Once the carrier confirms it is done, run these five checks from a phone outside your network — a personal mobile is ideal, because it proves the call is arriving the way a customer’s would.

What porting does not move

The number arrives. Two things attached to it do not, and both need attention the same day.

The E911 address: A VoIP number needs a registered emergency address for each user or location. Confirm it in the new system rather than assuming the old carrier’s record travelled with the number. It did not.
Business texting registration: Texting from a US local number requires 10DLC brand and campaign registration, and it does not carry over — least of all from a landline, which never had it. Submit early, because carrier approval can take days or weeks.

Common mistakes that get ports rejected

Each of these is routine, and each one costs a week.

Using the website address instead of the CSR address: The most common rejection there is. Validation compares against the carrier’s record, not against reality.
An authorized-name mismatch: “Acme LLC” and “Acme Holdings LLC” are two different companies as far as the check is concerned.
Cancelling the old service early: The carrier can release the numbers, and recovering a released number is slow at best. The ported numbers leave the old account on their own.
Forgetting the fax or alarm line: Anything left on the account goes dead when the account closes. Lifts and alarm panels are the ones nobody remembers until they stop dialling out.
Porting wireless numbers without the PIN: The number transfer PIN is separate from the account password, and it can expire.
Configuring routing after the port: The numbers arrive and land in a system nobody set up. Do it in step three.

Six common porting mistakes shown as incorrect and corrected pairs: wrong service address, authorized-name mismatch, cancelling old service early, forgetting fax or alarm lines, missing wireless PIN, and routing not configured. — All six are preventable in the week before you submit.

Where to go from here

A clean switch comes down to three things. Pull the CSR, copy it into the LOA exactly, and keep the old line active until the FOC date passes. Do those and most ports finish without a customer noticing anything happened.

Porting is free on every DialPhone plan, local and toll-free, and a temporary number comes with it so you can build and test your call flow while the port runs.

How to Port a Business Phone Number Without Dropping a Call