> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://help.1lookup.io/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# 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.