Phone data
for developers.

Validate numbers, standardize formats, and understand the phone data behind every contact.

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Example number

Number details

Sample data

E.164: +14165550123
Country: Canada
Line type: Fixed line or mobile
Numbering plan: Valid

Example only. No lookup or credits used.

Example complete

Integrate in a few lines.

A phone number in. Structured data out. Use a straightforward HTTP request in the language you already work with.

curl -X POST 'https://YOUR_API_HOST/v3/verify' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"phone":"+14165550123","mode":"static"}'

POST /v3/verifyYour key stays on your server.

Static validation uses 1 credit. Current-carrier lookup uses up to 10. Explore the API

Start with a real example.

Try a free numbering-plan check. No account or credits needed.

+1 416 555 0123

Every good contact starts here.

Run a check to see the standardized number, country and line type.

Clean the list.
Keep the context.

Turn inconsistent phone columns into standardized contact data. Preview your CSV, choose a column, and download the results alongside your original fields.

Check up to 1,000 rows per file for free using local numbering-plan validation. Use account processing when you need carrier data.

Clean a contact list

Sample CSV transformation

Original phone	E.164
(416) 555-0123	+14165550123
020 7946 0018	+442079460018

Country selected per import · Original columns preserved

Example ChatGPT prompt

“Check this contact’s phone number and give me the standardized format and line type.”

Phonecheck connectionSetup guide

Phone intelligence,
in the conversation.

Connect Phonecheck to ChatGPT with a secure account connection. Check numbers from a conversation using the same credit balance as your dashboard and API.

You control the connection and can revoke access. Follow the setup guide for current availability.

Connect to ChatGPT