What Is Phone Number Porting?

Phone number porting is the process of transferring ownership of a telephone number from one carrier (the "losing carrier") to another (the "gaining carrier") without changing the number itself. Number portability is a legal right in most countries — your carrier cannot refuse a valid port-out request.

Porting matters because phone numbers become part of your brand. Customers have them saved, they appear on invoices and business cards, and websites link to them. Losing a number when switching providers can mean losing calls for weeks or months.

How Long Does Porting Take?

Port duration varies by country and carrier:

  • UK, Ireland: 1-5 business days
  • Germany, France, Netherlands, Belgium: 5-15 business days
  • US (local numbers): 3-7 business days
  • US (toll-free): 1-4 business days
  • Spain, Italy, Portugal: 10-20 business days
  • Other EU countries: typically 10-15 business days

The port date is coordinated with both carriers. On the port date, the number switches at a specific time (usually midnight local time), so you need to be ready to accept calls through the new carrier the next business day.

What You Need to Port a Number

For most ports, the gaining carrier (in this case DIDfarm) will ask for:

  1. Letter of Authorization (LOA) — a signed document authorizing the port. DIDfarm provides a pre-filled template.
  2. Copy of the current invoice — less than 3 months old, showing the number(s) and account details
  3. Account number with the losing carrier
  4. Service address — the billing address registered with the losing carrier
  5. Port-out PIN (US/Canada only) — you request this from your current carrier

For business accounts, we also need a copy of your company registration (KvK, HRB, Companies House, etc.).

Step-by-Step Porting Process

1. Request a Quote

Send your list of numbers to DIDfarm support. We check:

  • Portability (some numbers, especially toll-free and national, may be non-portable)
  • Regulatory requirements per country
  • Expected port date and any fees

2. Submit Documentation

Sign the LOA and upload the required documents through the DIDfarm portal. DIDfarm submits the port request to the losing carrier within 1 business day.

3. Wait for Carrier Approval

The losing carrier has a statutory window (usually 5-15 business days) to either approve or reject the port. Rejection reasons include:

  • Mismatched account information (typo in address, company name, etc.)
  • Outstanding bills on the account
  • Account is locked or under contract with early termination fees
  • Number is not in the losing carrier's range

If rejected, DIDfarm will tell you exactly what to fix and resubmit.

4. Confirm the Port Date

Once approved, you get a firm port date. You need to configure your new DIDfarm SIP trunk in advance so it is ready to accept calls the moment the number switches. See the 3CX setup guide if you use 3CX.

5. Port Day

On the port date, the losing carrier releases the number. DIDfarm's upstream carrier takes ownership, and the number is routed to your configured SIP trunk. You should test a call within 15 minutes of the port completing.

There is typically a 5-30 minute window where calls may fail during the actual switch. Plan for it and warn your team.

How to Avoid Downtime

  • Pre-configure your new trunk — have the DIDfarm side fully working before the port date
  • Port outside business hours — DIDfarm schedules most ports for 2 AM local time to minimize impact
  • Keep the old trunk active — do not cancel your old carrier until at least 48 hours after the successful port
  • Monitor the switch — have someone on hand to test calls immediately after the port completes

How Much Does Porting Cost?

DIDfarm does not charge porting fees for most European countries. Some countries (Germany, Italy) have upstream carrier fees ranging from €5 to €50 per number. The losing carrier may also charge a port-out fee — check your contract.

Compared to losing a number and starting over, porting is almost always worth the small fee.

Gotchas and Edge Cases

  • Toll-free numbers — these port separately from local numbers and follow different rules (often faster)
  • Mobile numbers — usually portable, but the SIM card must be deactivated once the port completes
  • Private ranges — some private number ranges (e.g. some 0800 UK numbers in legacy carrier allocations) cannot be ported
  • Regulatory re-verification — countries like Germany may require you to re-submit identity documents after porting

Ready to Port?

Contact DIDfarm support with your list of numbers and current carrier, and we'll send you a quote and LOA template within 1 business day. If you're new to DIDfarm, create a free account first and add a SIP trunk — you'll need it for routing once the port completes.

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