Porting is the process of moving a phone number from one carrier to another. The number belongs to you, and the law requires the losing carrier to release it, but the process runs on paperwork, and a single mismatch between what you submit and what the old carrier has on file stops it cold. Here is how to do it once.
Never cancel the old service first
A number can only be ported while it is active. If the old account is canceled before the port completes, the number is released back to the carrier's pool and may be gone for good. Keep the old service running until the new carrier confirms the port is complete and you have made test calls on the new system. Then cancel, in writing, with the port confirmation attached so the final bill is prorated.
Get the customer service record before you start
Ask the old carrier for a CSR, the customer service record, for the account. It lists every number on the account, the billing name and address exactly as the carrier holds them, and the account number. The port request must match the CSR character for character: the legal company name, the service address, the account number and the authorized name. Most rejections are a suite number missing or a company name abbreviated differently.
Decide what to port, and what to let go
Walk the CSR against the inventory. Main numbers, published direct lines and fax numbers that still receive anything should port. Lines nobody recognizes should be checked before they are abandoned; alarm panels, elevators and credit card terminals often sit on forgotten analog lines. Decide line by line, and record the decision, because the old account closes once the port is done.
The letter of authorization and the timeline
The new carrier will send a letter of authorization, or LOA, which an authorized signer completes with the account details from the CSR and a copy of a recent bill. Simple ports of a few numbers complete in a few business days; ports of a main number block or numbers tied to a complex account take two to four weeks, and the old carrier can reject the request once or twice over mismatches before it goes through. Build that into the cutover date, and schedule the port for a quiet time of day with someone on site to test.
After the port
Make and receive test calls on every ported number, check that caller ID shows the right name, and update the directory listing, which does not move with the number. Then cancel the old service in writing and watch the next two bills; the old carrier should bill nothing beyond the port date, and the new one should match the order.
DemarcLabs keeps every phone number with its carrier, location and port status in the inventory, so the list for the CSR is already there and nothing is canceled before it has moved.