# Validate mobile numbers in bulk, before you spend on them

Bulk phone number validation: upload a CSV or paste your list and find out which mobile numbers are valid, invalid or undetermined. Clear result per row, CSV export, universal credits.

Number validation answers one question for every row of your list: is this mobile number valid and usable? Upload a file or paste the numbers and get a clean, exportable answer per contact.

## Cost

- 4 credits per number — minimum batch 500 numbers.

## Key points

- Bulk phone number validation from CSV, XLSX or pasted text
- Numbers normalised to international format
- One result per row, filterable and exportable to CSV

## What this check verifies

- Whether the number is written in a usable format once normalised to international notation.
- Whether the number corresponds to a valid mobile line according to the check performed.
- Whether the same number appears more than once in your list, so you only pay once.
- Whether the check could return a conclusive answer at the time it ran.

## The results you receive

Six possible outcomes, each with a precise meaning. Nothing is inferred beyond what was checked.

- **Valid**: The number resulted valid and usable as a mobile line at the time of the check.
- **Not valid**: The number did not result usable: it does not correspond to a valid mobile line.
- **Undetermined**: The check ran but could not return a conclusive answer for this number.
- **Invalid format**: The row could not be normalised into a phone number. It is reported and not charged.
- **Duplicate**: The number already appears in the same job. It is reported once and charged once.
- **Technical error**: The row could not be processed for a technical reason. It is not charged and the credits return to your wallet.

## From list to result

A short example with fictitious numbers, exactly in the shape you export.

### What you upload

- +39 34• ••• 1180
- +39 34• ••• 1180
- 0039-abc
- +49 15• ••• 7723

### What you get back

| Number | Result |
| --- | --- |
| +39 34• ••• 1180 | Valid |
| +39 34• ••• 1180 | Duplicate |
| 0039-abc | Invalid format |
| +49 15• ••• 7723 | Not valid |

## When to use it

- **Database cleaning**: Old CRMs and imported lists carry typos and dead records. Validation tells you which rows deserve a place in your database.
- **Pre-screening before campaigns**: Run validation before an SMS or messaging campaign so your audience count reflects numbers you can actually use.
- **Fewer unusable rows**: Removing rows that cannot work reduces failed attempts and makes campaign reporting easier to read.

## What this check does not mean

- It does not certify the identity of the person behind the number.
- It does not represent marketing consent: the lawful basis for contacting someone remains yours.
- It does not guarantee that a message will be delivered, read or answered.

## Number validation FAQ

**What format should the numbers be in?**

International format (for example +393401234567) is the safest. You can also set a default country so local numbers are normalised for you.

**How many numbers can I check at once?**

Lists are processed in bulk from a CSV, XLSX or pasted text. The app shows the number of valid rows and the credit cost before the job starts.

**Am I charged for invalid numbers?**

Invalid formats, duplicates and technical errors are not charged. Reserved credits for those rows return to your wallet automatically.

**Do you tell me the carrier or the line type?**

No. Today the service reports validity and usability of the line, not carrier or portability details.

**How long do results stay available?**

Every job stays in your check history with its results, and you can download the CSV again whenever you need it.

**Does the check contact the number?**

The workflow never asks you to send a message, and you do not connect your own SIM, phone or messaging account.

**Can a valid number become invalid later?**

Yes. A result photographs the status at the time of the check. For lists you reuse often, re-checking periodically is good practice.

**Can I use the results in my CRM?**

Yes. The CSV export includes the original number, the normalised number, the outcome and the credits charged, ready to be imported back.

## Validate your first list today

Create an account, upload a sample and check the quality of your database before your next campaign.

> Results describe the technical status detected at the moment of the check. They are not marketing consent and do not guarantee message delivery.

## Links

- HTML version: https://numerovero.online/en/number-validation
- Pricing: https://numerovero.online/en/pricing
- Create an account: https://numerovero.online/en/signup
- All products: https://numerovero.online/en/products
- Guides: https://numerovero.online/en/guides
- Machine-readable site overview: https://numerovero.online/llms.txt
- Related guide: https://numerovero.online/en/guides/phone-number-lookup-validation