> ## Documentation Index
> Fetch the complete documentation index at: https://developer.moltsets.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Getting Carrier-Verified Mobile Phones

> How to append verified mobile numbers with MoltSets — batching up to 100 profiles per call, budgeting external tokens, and reading the validation date.

`linkedin_to_mobile_phone` is the only phone endpoint in the API. It takes a LinkedIn profile and returns a carrier-verified mobile number with the date it was last verified.

```json theme={null}
{
  "mobile_phone": "+15551234567",
  "last_validated_at": "2026-03-04"
}
```

## Mobile only, by design

Only mobile numbers are returned — **no landlines, no VoIP**. Every result is a real device, which is what makes the output usable for SMS and direct dial rather than a switchboard you have to navigate.

The practical consequence: contacts whose only number is a desk line simply won't return a result. A miss here isn't a data gap so much as a filter working as intended.

## Batch up to 100 per call

The endpoint takes either a single URL or a batch:

| Parameter       | Type   | Use                                     |
| --------------- | ------ | --------------------------------------- |
| `linkedin_url`  | string | One profile                             |
| `linkedin_urls` | array  | Up to **100** profiles in a single call |

Batching is the single highest-leverage practice here. One call for 100 profiles instead of 100 calls cuts your request count by 99%, which matters because **every request counts toward your rate limit regardless of whether it returns data**.

```json theme={null}
{
  "linkedin_urls": [
    "https://linkedin.com/in/person-one",
    "https://linkedin.com/in/person-two"
  ]
}
```

For lists longer than 100, chunk into batches of 100 and pause briefly between them rather than firing everything at once. See [Rate Limits](/getting-started/rate-limits) for the per-plan ceilings.

## Budget external tokens first

<Warning>
  Mobile phone lookups **require external tokens**, at a cost of **10 external tokens per returned result**. This is a separate balance from your regular tokens, and it is the most expensive lookup in the API per result.
</Warning>

A 100-profile batch that resolves fully costs 1,000 external tokens. Plan runs against your balance before you start:

| Plan          | External tokens |
| ------------- | --------------- |
| \$0           | 100             |
| \$27 / month  | 100 / month     |
| \$97 / month  | 500 / month     |
| \$997 / month | 2,500 / month   |

`get_account` and `get_billing` are **free** and never cost tokens. Read `external_token_balance` before a large run so a job doesn't stall halfway through.

You're only charged for results that come back — profiles with no mobile on file cost nothing.

## Qualify before you enrich

Because this is the priciest per-result lookup, it pays to narrow the list before calling it rather than after. Run your [people search](/best-practices/searching-for-people) filters first and enrich only the contacts you'd actually call:

1. `search_people` with `seniority`, `department`, and location filters
2. Review `results.total` and tighten until the list is the size you intend to work
3. Batch the resulting LinkedIn URLs into `linkedin_to_mobile_phone`, 100 at a time

Enriching a 5,000-row list "just in case" is how an external token balance disappears in one afternoon.

## Read the validation date

`last_validated_at` is the date the number was last confirmed active and in service.

<Note>
  Unlike email, MoltSets does **not** assign a risk score or confidence grade to phone numbers. The validation date is the signal — a number confirmed last week carries more confidence than one confirmed a year ago, and it's your call how much weight to give it. See [Understanding Phone Number Validation](/moltsets-data/phone-number-validation).
</Note>

Set a staleness threshold that matches the channel. Cold calling a number verified 18 months ago wastes a dial; sending SMS to one wastes money and can generate complaints.

## Related

<CardGroup cols={2}>
  <Card title="Phone Number Validation" icon="phone" href="/moltsets-data/phone-number-validation">
    What the validation date does and doesn't tell you.
  </Card>

  <Card title="Rate Limits" icon="gauge" href="/getting-started/rate-limits">
    Batching, backoff, and per-plan ceilings.
  </Card>
</CardGroup>