Moving Your Business Phone Number to VoIP: Porting Step by Step
Your business phone number is printed on your van, your website, your invoices and years of customer contacts. The good news is that switching to a VoIP provider does not mean giving it up. This step-by-step guide walks you through number porting, so you can move your existing number to a new phone system without missed calls or nasty surprises.
Key takeaways
- In the US and UK, businesses can usually keep (port) their phone numbers when switching providers, and the new provider normally handles the port request.
- Do not cancel your old phone service until the port is complete, or you risk losing the number.
- Most delays come from mismatched details, so copy your account name, address and account number exactly from a recent bill.
- Plan the switch for a quiet day, test every number afterward and update texting, emergency address and voicemail settings.
Maybe your landline contract is ending, your team now works partly from home, or you simply want calls to ring on laptops and mobiles as well as a desk phone. Whatever the reason, the scariest part of moving to VoIP is usually the number. Customers have saved it, it sits on your Google Business Profile and it is printed on everything from business cards to signage.
Late January is a sensible time to tackle this. Many businesses are reviewing contracts and costs for the year ahead, and for many trades and retailers the phones are a little quieter than in December. We will not cover how VoIP works or how to choose a plan in depth here. This guide focuses on the move itself: getting your number from the old provider to the new one safely.
What number porting is and who handles it
Number porting is the process of transferring a phone number from one provider to another. You keep the number; only the company that carries your calls changes. In the US and the UK, rules let businesses port their numbers when switching providers, and in most cases you start the process with your new provider, not the old one. The new provider submits the request, the old provider releases the number, and calls begin routing to your new system on the agreed date.
Most kinds of numbers can usually be ported, including local landline numbers, mobile numbers and many toll-free or non-geographic numbers. However, not every provider supports every number type or every area, so check before you sign anything.
Common terms you will see
- Losing provider: the company you are leaving.
- Gaining provider: the new VoIP company you are moving to.
- Letter of authorization: a form, often signed electronically, that gives the new provider permission to request the port on your behalf.
- Port date: the day your number switches to the new provider.
- Temporary number: a number the new provider may give you so you can set up and test the system before the port completes.
Before you start: check eligibility and gather details
Most failed or delayed ports come down to paperwork. Spend 30 minutes collecting the right information and the rest of the process gets much easier.
- Confirm the new provider can take your number. Ask your shortlisted providers, such as RingCentral, Dialpad, Nextiva, Zoom Phone or Google Voice, whether they support porting your specific number type and location. Check current features, pricing and privacy policies directly with each provider.
- Get a recent bill from the current provider. You will need the exact account holder name, service address, account number and the list of numbers on the account.
- Ask for an account PIN or passcode. Many providers, especially mobile carriers, require a port-out PIN or code. Request it in advance.
- Check your contract. Look for an end date, notice period or early termination charge. Porting the number does not cancel the contract terms.
- List every number you use. Include main lines, fax numbers, direct lines, alarm or card terminal lines and any numbers that forward elsewhere.
- Decide what moves and what stays. Some lines, such as alarm system or card machine lines, may need a different solution. Ask the vendors of those systems before you move them.
Common mistake
Cancelling your old phone service first. If the account closes before the port completes, the number can be released and may be very hard or impossible to get back. Keep the old service active until the new provider confirms the port is finished and you have tested incoming calls.
The porting process step by step
Every provider has its own portal and forms, but the process follows a similar pattern.
- Sign up with the new provider. Choose your plan and set up users, but do not cancel anything yet.
- Use a temporary number while you build. Set up call routing, menus, voicemail and user devices on the temporary number so you can test without touching your live line.
- Submit the port request. Enter your details exactly as they appear on your current bill. Upload a copy of the bill if asked and sign the letter of authorization.
- Watch for questions or rejections. If the losing provider rejects the request, it usually gives a reason, such as a name or address mismatch. Fix it and resubmit quickly.
- Agree the port date. Once accepted, you will get a scheduled date. Choose a quieter day and avoid your busiest hours where you can.
- Prepare the team. Make sure everyone has the new app installed, can log in and knows how to answer, transfer and check voicemail.
- Port day: test immediately. Call each ported number from a mobile phone. Check that calls ring the right people, menus work and voicemail picks up.
- Close the old account. Only after successful testing, contact the old provider about remaining services and final bills.
Pro tip
Timelines vary by provider, number type and how many numbers you are moving. Ask the new provider for a realistic estimate when you sign up, and avoid scheduling the switch right before a big launch, a sale or a busy season.
A porting tracker template
If you are moving more than one number, a simple tracker keeps everyone on the same page. Copy these columns into a spreadsheet. The rows below are made-up examples for illustration only.
| Number (example) | Used for | Current provider | Account details checked? | Port request status | Port date | Tested? |
|---|---|---|---|---|---|---|
| Main line (555) 010-0001 | Front desk and website | Old landline company | Yes, matches bill | Accepted | Tuesday, week 3 | Pending |
| Owner mobile (555) 010-0002 | Direct client calls | Mobile carrier | Port-out PIN requested | Submitted | TBC | No |
| Fax line (555) 010-0003 | Supplier orders | Old landline company | Yes | Not porting, cancel after review | n/a | n/a |
Add a "notes" column for rejection reasons and contact names. It saves a lot of repeat explaining on support calls.
After the port: settings people forget
Once calls are flowing to your new system, a few settings still need attention. These are the ones that tend to cause trouble weeks later.
Emergency calling address
VoIP phones are not tied to a physical line the way traditional landlines are, so providers ask you to register an address for emergency calls. Make sure each user and device has the correct location, and update it if people work from home or move offices. Check your provider's current guidance and local rules.
Business texting
If you plan to send texts from your ported number, set that up separately. In the US, business texting from local numbers requires A2P 10DLC registration through your provider, and the TCPA requires prior express written consent for marketing texts. In the UK, PECR consent rules apply to marketing texts. Start registration early, because texting may not work until it is approved.
Voicemail, menus and hours
Record a fresh greeting, set opening hours and holiday routing, and decide where calls go when nobody answers. Old voicemails usually do not transfer, so save any you need before the port.
Listings and integrations
Because the number stays the same, your website and listings should not need changing. Still, double-check click-to-call links, booking tools and any CRM or help desk connections that log calls.
Hypothetical example
Imagine Dana, who runs a three-person plumbing business. Her landline contract ended in January, and her team wanted calls on their mobiles while on jobs. She picked a VoIP provider, built a simple call menu on a temporary number and had her team test the app for a week. Her first port request was rejected because the bill listed her old trading name. She resubmitted with the exact name from the bill, and the port went through on a quiet Tuesday morning. She tested every line from her mobile, then closed the old account. Customers kept calling the same number and never noticed the change.
Troubleshooting common porting problems
- Request rejected for mismatched details. Copy the account name, address and account number exactly as shown on the bill, including suite numbers and spelling. Ask the old provider for a copy of the account record if unsure.
- Missing PIN or passcode. Contact the losing provider and request a port-out PIN or code, then resubmit.
- Only some numbers moved. Check that every number was listed on the request. Some providers handle main and extra numbers differently.
- Calls ring the old system after port day. Changes can take a little time to spread. If the problem continues, open a ticket with the new provider and note the time of each failed test call.
- Outbound calls show the wrong caller ID. Update caller ID settings in your new provider's admin portal so the ported number displays.
A quick note: this guide is general information, not legal or contract advice. If your contract has complex terms, early termination charges or regulated lines such as alarm systems, ask the providers involved or a qualified professional before you switch.
Your number porting checklist
- Confirm the new VoIP provider can port your number type and area
- Get a recent bill with the exact account name, address and account number
- Request a port-out PIN or passcode if your provider uses one
- Check contract end dates and early termination terms
- List every number and decide which ones move
- Set up and test the new system on a temporary number
- Submit the port request and sign the letter of authorization
- Schedule the port for a quiet day and brief the team
- Test every number on port day before closing the old account
- Update emergency addresses, texting registration and voicemail
Frequently asked questions
Will my phone go down during the port?
Most ports happen with little or no interruption, but a short gap can occur while the switch takes effect. Schedule the port for a quiet time, keep a mobile handy and let your team know what to expect.
Can I port a mobile number to a VoIP system?
Often yes, but it depends on the provider and number type. Ask the new provider before signing up, and remember that the number will then work through the VoIP app rather than your mobile plan.
Do I contact my old provider to start the port?
Usually not. The new provider normally handles the port request. You may need to contact the old provider for a PIN, an account record or to close the account after the port completes.
What if my port request keeps getting rejected?
Ask the new provider for the exact rejection reason. It is most often a detail mismatch, such as name, address or account number. Get the official account record from the old provider and copy it exactly.
Related reading
The bottom line
Moving your business phone number to VoIP is mostly careful paperwork. Confirm the number can be ported, copy your account details exactly, build and test on a temporary number, and keep the old service running until the port is complete. Then tidy up emergency addresses, texting and voicemail.
Pull out your latest phone bill this week and start the tracker. With a little preparation, your customers will keep dialing the same number while your team enjoys a more flexible phone system.
