Skip trace: find a phone number from a name and address

Skip tracing takes a name and postal address and appends a phone number for that person. Use it when your records have someone's mailing details but no way to reach them by phone.

What it tells you

• Whether a matching contact was found for the name and address you sent.
• The phone number appended to that contact.
• What kind of line that number is, for example mobile.

What you need to provide

All five of these, sent inside the input object:

• First name of the contact.
• Last name of the contact.
• Street address.
• City.
• ZIP code.

What it costs

10 credits per lookup. Live per-product costs are shown on the Billing page in your dashboard.

How to run it

• In the dashboard: Skip Trace
• From your code: POST /v1/phone-append, then see the Developer Hub at app.1lookup.io/developer-hub.

Good to know

• Every one of the five inputs is required, so records missing a city or a ZIP cannot be run until you fill the gaps.
• A lookup can come back with no match. That means no contact was found for the details you sent, not that the person has no phone.
• Results are point-in-time. People move and change numbers, so an appended number can go stale, and an old address makes a match less likely.
• Email Data Append takes the same five inputs and returns the email address on record instead.
• This is personal data about an identifiable person. Use it for legitimate business purposes only.

Updated on: 24/08/2026