Lead generation
Phone checks for lead generation
A mistyped or made-up number costs you the follow-up. Check each lead's phone as it arrives through the API, or clean a whole export in one upload.
Upload a listWhat you get
What you get back
Every field below is in the API response, with the type to expect.
| Field | Type | What it means |
|---|---|---|
valid | boolean | Whether the number can be a real one. This is a format and numbering check, not proof that anyone answers. |
verdict | string | The short answer for the row: textable, callable, invalid or unknown. |
reason | string | Why the verdict is what it is, such as mobile, bad_format or outside_coverage. |
line_type | string | null | The kind of line: mobile, fixed_line, voip, toll_free and the other types a carrier reports. null when unknown. |
voip | boolean | true for an internet (VoIP) number. Texting one is unreliable. |
carrier | string | null | The carrier that holds the number, as our data source names it. |
Verdicts
A verdict for every row
Read the verdict first. The reason field says how we got there.
| Verdict | What it means | What to do with the row |
|---|---|---|
| Valid · Mobile | A mobile number. It can be called and texted. | Keep it. Whether you may text it depends on consent, and this check does not look at consent. |
| Valid · Landline | A line that can be called: a landline, a toll-free number, VoIP or another type. A VoIP number is flagged because texting it is unreliable. | Call it. Do not count on texts, and send VoIP rows to your call list. |
| Invalid | Not a working number. It is not a real phone number, or no carrier holds its exchange. | Drop the row. If the number looks like a typo, fix it and check it again. |
| Unknown | We could not tell what the number is. You are not charged. | Set the row aside and check it again later if it matters. |
Verdicts describe reachability. They are not compliance checks.
How it works
How it works
Four steps, and none of them needs a call with us.
- Step 1
Upload a CSV
Drop in a CSV file. We read the header row and look for the column that holds the phone numbers.
- Step 2
Confirm the column
We pick the phone column and show a few values from it. Change it if we guessed wrong.
- Step 3
See the cost before you pay
You see how many unique rows there are and what they cost against your balance. Duplicates and empty rows are free, and nothing is taken until you confirm.
- Step 4
Download by verdict
Get the full file plus one file per verdict. Rows that come back unknown are returned to your balance, and we email you when it is done.
Limits
What this check cannot tell you
Knowing where a check stops is what lets you trust the part that works.
- Live data covers numbers in the United States and Canada. A valid number anywhere else gets a format check, the verdict unknown and no charge.
- Carrier answers are cached, so a number that changed carrier very recently may still show the old one.
- We do not say who owns a number. A carrier is a company, not a person, and we do not look people up.
- A number that was real once and is now out of service can still come back callable. A carrier lookup shows what kind of line a number is, not whether anyone picks up.
- Verdicts do not cover consent or Do Not Call lists. Whether you may contact a number is a separate question that this check does not answer.
FAQ
Questions about this check
Short answers. If yours is not here, write to support@numberlookup.io.
How do I get an API key, and what does a call cost?
Create an account, open API keys in your dashboard and make a key. It is shown once, so copy it then. A call to the phone or IP endpoint costs 1 credit, or nothing when the result is unknown or the call fails. New accounts start with free credits and need no card.
What am I charged when a result is unknown?
Nothing. A result of unknown costs 0 credits. So does input that is not a phone number at all, an empty row and any error. In a bulk list, duplicate rows are free, and rows that come back unknown are returned to your balance when the list finishes.
What does each verdict mean?
Textable is a mobile number, which can be called and texted. Callable is a line that can take calls, such as a landline, a toll-free number or a VoIP number. Invalid is not a working number. Unknown means we could not tell, and you are not charged. A verdict says whether a number can be reached. It says nothing about whether you may contact it.
What happens to my uploaded lists?
The file and the result files are kept while the job runs and for a fixed number of days after it finishes, then deleted automatically. The number of days is on this site and on your results page. The numbers in your list sit in those files and nowhere else we keep: the lookup cache stores a keyed hash of each number with what the carrier said, not the number. We email you when the job is done.