Check E.164 numbers in bulk before outreach and return number and activation signals. Use the result to flag records for review, clean lists and maintain CRM data quality; a returned signal does not guarantee a call or message will connect.
This is the official NumDetect example repository for one bulk product, number_validation_batch. It is an asynchronous task: upload a file, get a task id immediately, poll the task, and download the result file when it finishes.
- Product page: https://numdetect.com/products/number_validation_batch
- API documentation: https://numdetect.com/api-docs
- API base URL:
https://numdetect.com - Authentication:
X-API-Key - Get an API key: https://numdetect.com/register
- Registration filtering
- List cleaning
- CRM hygiene
| Column | Example | Meaning |
|---|---|---|
number |
17253100591 |
The original submitted E.164 number. Use it to match and trace the result back to the uploaded record; the field alone does not establish that a number can be contacted. |
activated |
yes |
Whether this check returned an activation signal. Combine it with your own consent, source and recent-interaction data for review or segmentation, not as a guarantee of connection or delivery. |
The result is a point-in-time signal, not a verdict, and not identity data. It describes what the provider reported at the moment the task ran.
Upload a .txt or .csv with one phone number per line, 500–100,000 valid entries. A number list must come from a single country, given as country — the upstream uses it to expand bare national numbers.
curl -X POST 'https://numdetect.com/api/v1/bulk-tasks' \
-H 'X-API-Key: YOUR_API_KEY' \
-F 'product=number_validation_batch' \
-F 'country=US' \
-F 'file=@numbers.txt'The response returns the task id and status=processing, along with the server-side quote taken before processing starts.
curl -fsS 'https://numdetect.com/api/v1/bulk-tasks/TASK_ID' -H 'X-API-Key: YOUR_API_KEY'status is processing, success or failed — there is no progress percentage to poll for. Do not poll more often than once every 30 seconds. When the task succeeds the response carries the result-file download link.
POST /api/v1/bulk-tasks (this repository) takes a file of 500–100,000 entries and answers later — that is the shape for list cleaning, campaign preparation and enrichment runs. A realtime check (POST /api/v1/check, or POST /api/v1/batch-check for up to 100 identifiers) answers inside the same HTTP response, for a signup form or a live lookup. The two are separate endpoints and are not interchangeable; see the other repositories under numdetect.
The whole file is reserved on submit. When the task finishes you are charged only for the entries that were actually checked and the remainder is returned. A failed task is refunded in full.
| Limit | Value |
|---|---|
| Entries per task | 500–100,000 |
| File formats | .txt, .csv, one entry per line |
| Products per task | 1 (number_validation_batch) |
| Country | required, exactly one per task |
| Poll interval | no more than once per 30 seconds |
40000/40001 are request or file errors; 40100 is an invalid key; 40200 is insufficient balance; 42900 is rate limited — honour Retry-After; 50300 is temporary maintenance. GET /api/v1/balance returns the current balance in data.balance_micros.
Keep the key on a trusted server and read it from NUMDETECT_API_KEY. Never commit it or expose it in production browser code.
| Language | Example |
|---|---|
| Python | examples/python |
| Node.js | examples/nodejs |
| Go | examples/go |
| Java | examples/java |
| C# | examples/csharp |
| PHP | examples/php |
| Shell / curl | examples/shell |
- This product: https://numdetect.com/products/number_validation_batch
- All products: https://numdetect.com/products
- Documentation: https://numdetect.com/api-docs
- Registration: https://numdetect.com/register
- Pricing: https://numdetect.com/pricing
- OpenAPI contract:
openapi.yaml - License: MIT for the sample code
Submit only data you are authorized to process, and comply with applicable privacy laws and platform terms. Report the signal you received as a signal; do not relabel it downstream as a conclusion it does not support.
Last reviewed: 2026-09-22 · Maintained by NumDetect. Canonical documentation: https://numdetect.com/api-docs