Yes, if you port the number to another carrier before you cancel, or it already sits in a carrier account in your name. Cancel first and you can lose it. Twilio lets you reclaim a released number for 10 days, closing a Twilio account stops calls at once and deletes its data in 30 days, and Vapi says its free numbers cannot be ported to another carrier at all. Your call recordings need the same order: export them before the account closes.
I read pages from the help centers, docs and terms of Twilio, Telnyx, Vapi, Retell and Bland, plus the FCC’s porting guide, on 1 October 2026. When we scope AI call answering for home services, the exit goes in the plan early: the agent can be rebuilt elsewhere; the number can only be moved.
Canceling is a button. Keeping the number is a port that has to start while the account is still open.
Key numbers
| Item | Number |
|---|---|
| Twilio, days to reclaim a released number | 10 days |
| Twilio, data deleted after an account closes (calls and messages stop at once) | 30 days |
| Twilio port-out, Account SID characters to give | last 8 |
| Twilio port-out PIN, US local numbers (requested from [email protected]) | 4 or 5 digits |
| FCC, simple port processing time (generally a single line) | 1 business day |
| Vapi, days to cure a material breach (at least; three listed cases allow suspension without notice) | 10 days |
| Retell, number fee per month ($5 toll-free) | $2 |
| Retell, past-due invoice to shutdown risk | 7 days |
| Retell, call data retention setting (default keeps data indefinitely) | 1 to 730 days |
| Bland, number fee per month through the API | $15 |
Read on 1 October 2026 from the Twilio and Telnyx help centers, the Vapi and Retell docs, the Vapi, Retell and Bland terms of service, Bland's API docs and the FCC porting guide.
Who holds the number decides whether it can leave
Telnyx’s help center explains why it matters whose account the number sits in. A reseller leases numbers from a carrier and resells them under its own brand, so a port away from one needs the underlying carrier’s account number and PIN, not your login to the reseller’s dashboard. On the platforms I read, an AI receptionist’s number is one of three kinds.
A number in your own Twilio or Telnyx account. You hold the account, so the port is yours to run. Twilio’s port-out article lists what the new carrier will typically ask for: the last 8 characters of your Account SID, a PIN of 4 or 5 digits for US local numbers, requested from [email protected], and Twilio’s service address for numbers bought from Twilio. Twilio then emails the account holder to confirm. Telnyx uses one of the numbers being moved as the account number and emails you a link to the request.
A number the AI vendor bought for you. Retell sells Twilio and Telnyx numbers at $2 a month ($5 toll-free), needs no telephony account of yours, and its docs call them yours once purchased. With no carrier account in your name, the carrier-level credentials are the vendor’s to hand over. Retell’s purchase, billing and account pages explain how to release a number; none of the three describes a port-out. Bland sells numbers through its API at $15 a month, and its terms, updated 28 August 2026, do not mention phone numbers at all.
A free number from Vapi. Vapi’s free numbers are US only and take inbound calls only. Its docs say it plainly: the number sits on Vapi’s carrier accounts, there is no account number or port-out PIN to request, and “the number cannot be ported to another carrier”. Vapi’s advice is to buy or port a number into your own carrier account and import it.
The mistake: canceling before the port is done
On Twilio and Retell a number is billed monthly until it is released, and both vendors’ steps for stopping charges include releasing it. Retell’s terms add that to cancel you must delete the workspace or remove subscription items such as phone numbers before the period ends, or the plan renews. On Twilio a released number can be reclaimed for 10 days, and closing an account is permanent: calls and messages stop that moment.
A port needs the opposite order. The FCC tells consumers not to end service with the old company before starting with the new one. Twilio asks you not to release numbers during a port-out, because they must be active for the port to succeed, and to switch off their emergency configuration before you submit it. FCC rules require a simple port, generally a single line, to be processed in one business day.
Owing money does not block a port, according to the FCC. Once you ask a new company for service, the old one cannot refuse to port your number even if you owe a balance or a termination fee, though it may charge a porting fee. Telnyx adds that most providers are required to tell you the underlying carrier, account number and PIN, and that an obstructive one may be breaking FCC porting rules. All of it assumes the number is still active.
You can also leave without choosing to. Retell’s account page says a past-due invoice puts the account at risk of automatic shutdown in 7 days. Vapi’s terms allow suspension without notice in three listed cases, such as a security risk, and give at least 10 days to cure a material breach before terminating for one.
Release the numbers, delete the workspace, close the account.
Retell’s stop-charges steps say to release numbers; its terms say to remove them before the period ends.
Port the numbers out, export the recordings, then cancel.
Twilio wants numbers active during a port-out; the FCC says not to end old service before starting new service.
Your recordings run on a different clock
The number is half the exit; the other half is every call the agent took. Retell keeps call data indefinitely unless you set a per-agent retention period, from 1 day to 730 days, after which recordings, transcripts and logs are deleted for good; its docs say to pull what you need by webhook or API first. Deleting a Retell account removes all associated data and cannot be undone.
Vapi’s terms, updated 14 September 2026, say you own the transcripts and recordings the service produces for you, and that after termination you may lose access to the account and its files may be deleted. Bland’s terms let it terminate at any time and for any reason, after which you may no longer reach the account or its files. Twilio ends access to logs the moment an account closes and deletes its data 30 days later. Storage fees are covered in our note on call recording storage cost.
Owning a recording you cannot reach is a thin right. Vapi already offers the fix: its recording settings can write to your own S3 or Google Cloud Storage bucket instead of Vapi’s cloud.
Four moves to make before you sign
Keep the number in a carrier account in your name
Buy or port it into Twilio or Telnyx under the business, then import it into the agent platform. Do not publish a vendor’s free or bundled number on your website or ads.
Write down the port-out details on day one
Underlying carrier, account number, PIN and service address. On Twilio that is the last 8 characters of the Account SID and a PIN from [email protected]; on Telnyx, one of the numbers serves as the account number.
Send recordings to storage you control
Point the platform at your own bucket, or capture every call by webhook as it ends, and set retention on purpose instead of accepting the default.
Leave in this order
New carrier first, port request submitted, the port-away confirmation answered, the port complete, the data exported. Only then release numbers or close the account.
The bottom line
The cancel button and the port request pull in opposite directions: one stops billing by releasing the number, the other only works while the number is active. Keep the number in a carrier account in your name and changing platforms is a re-point, as our guide to porting a number to an AI receptionist sets out. Leave it in the vendor’s account and your exit depends on the vendor.
I have built inbound and outbound calling for more than 200 businesses, and the setup I recommend fixes the exit before launch: the number in the client’s own carrier account, the recordings in its own storage. That is how we scope AI receptionists for home services. I am not a lawyer and this is not legal advice.