Two kinds of phone number. One is a real SIM.
Mobile lines are real SIMs on a mobile network, for the services that turn VoIP numbers away. Standard numbers are US local VoIP and ready in seconds. Your agents and tests read both through the same inbox and API.
Mobile and Standard, side by side.
Mobile
Real SIM line
- What it is
- A real SIM line on a mobile network.
- Use it for
- Services and sign-in flows that only text mobile numbers.
- Ready in
- About five minutes, while the new line joins the network.
- Picking one
- Choose an area code. The network assigns a number in or near it.
- Claimed from
- The web app.
- Texting out
- Texts go out from the line itself, within the sending limits.
- Releasing
- Request a release and our team completes it. The number doesn't come back.
- Included
- On every plan, from 1 on Starter to 10 on Scale.
Standard
US local VoIP
- What it is
- A US local VoIP number.
- Use it for
- Most tests of your own app, where any number that receives texts will do.
- Ready in
- A few seconds.
- Picking one
- Search by area code or state, then pick the exact number.
- Claimed from
- The web app, the API, the CLI or MCP.
- Texting out
- Texts go out through a Mobile line you link to it.
- Releasing
- Release it yourself in seconds. The carrier may give the number to someone else.
- Included
- On every plan, from 3 on Starter to 20 on Scale.
No number is accepted by every service. Some services only text mobile numbers, and that is what Mobile lines are for. Check the services your product depends on. How to choose between VoIP and a real SIM
From claim to first code.
Name the number, pick an area code and decide who can see it. A Standard number connects in seconds. A Mobile line joins the network in about five minutes, and the app shows each step as it goes. You can leave the page; the number is ready when you're back.
From then on, every text it receives lands in your inbox with the code pulled out, and your agents and tests can read it the moment it arrives.
Name it
Area code (optional)
You get a new SIM line with a number in or near it. Setting up takes about five minutes.
Decide who reads each number.
Share a number with the whole workspace, or only with the people, test keys and agents you choose. Owners and admins can always open it. A key reads only the numbers it has been given.
Each number can also forward its codes to email, a teammate's phone or a Slack channel.
Sign-in tests
+1 415 555 0142
Who can use it
- SLSena LindqvistReads codes
- TBTheo BrandtManages access
- ci-signinTest key · read only
- build-agentAgent · read and send
Acme's owners and admins can always open it. No one else can.
Read it from anywhere.
Every number works the same way from the SDK, the CLI, the MCP server and the HTTP API. Mark the number, trigger the text, then read the code. Signed webhooks tell your own systems when a text arrives.
Texting out, inside a closed loop.
Numbers can text people and numbers your workspace already knows, at a capped pace, so the lines stay trusted.
Who you can text
- Your workspace's own numbers
- Your teammates' verified phones
- Anyone who texted your workspace in the last 30 days
- Up to 5 outside numbers you add yourself
Limits
- 10 texts a minute and 100 a day per number
- 200 texts a day per workspace
- Up to 3 SMS segments per message
Steady, closed-loop sending is what keeps these lines trusted by the networks that carry them. Phonekit is for testing and running your own product, not bulk or marketing texts.
Questions
Is a Mobile line really a SIM?
Yes. Each Mobile line is a real SIM line on a mobile network. Standard numbers are US local VoIP, and the app labels every number with its kind.
Will a Mobile number work with every service?
No number is accepted by every service. A Mobile line is for services that only text mobile numbers. Each service sets its own rules, so check the ones your product depends on.
Can I choose the exact Mobile number?
You choose the area code. The network assigns a number in or near it when the line activates. With Standard numbers you pick the exact number.
Why does a Mobile line take about five minutes?
It's a new SIM line joining a mobile network. The app shows each step, and you can leave the page while it finishes.
Can I claim numbers from the API?
Standard numbers, yes: from the API, the CLI or MCP. Mobile lines are claimed in the web app. Once a number is ready, both kinds read the same way everywhere.
Can a Standard number send texts?
Yes, through a Mobile line you link to it as its sending line. Texts go out from that line, within the same limits.
Where are the numbers from?
Every Phonekit number is a US number. Within the sending limits, they can text US and Canadian numbers.
How long are messages kept?
Messages are encrypted at rest and kept 30 days from when they arrive. Releasing a number stops new messages but doesn't reset that clock.
Do numbers take calls or picture messages?
No. Phonekit numbers send and receive SMS. Calls and picture messages aren't supported.
Keep reading
- VoIP number or real SIMA plain comparison of VoIP numbers and real SIM lines for SMS verification, with when to choose each, when to keep or release a number, and a checklist.
- Plans and number pricesPhonekit plans start at $29 a month per workspace, with Standard numbers and real SIM Mobile lines, the SDK, CLI, MCP server and API, and a shared inbox on every plan.
- Numbers in the APIDiscover allowances, manage authorized lines, immediately read fresh SMS, send texts inside your own closed loop, and subscribe to selected-line webhooks through one API.
Get a number.
Tell us what you're testing. We'll set up your workspace.

✓ sign-in with SMS code (4.2 s)