Microsoft Bulk Number Checker API: Fast Phone Number Verification

Check whether the input phone numbers are registered with Microsoft services (Outlook, Skype, etc.)

Upload Detection File Code example:

curl --location 'https://api.checknumber.ai/v1/tasks' \
--header 'X-API-Key: API-KEY' \
--form 'file=@"./number.txt"' \
--form 'task_type="microsoft"'

Check Task Status Code example:

curl --location 'https://api.checknumber.ai/v1/gettasks' \
--header 'X-API-Key: API-KEY' \
--form 'task_id="task_id"'

Response for the upload detection file successful

{
    "task_id": "d4g8o46p2jvh04o9uolg",
    "status": "pending",
    "total": 2049,
    "message": "Task created successfully",
    "created_at": "2025-11-21T15:58:08.916446594Z"
}

Response for the processing status

{
    "created_at": "2025-11-21T08:27:09.933Z",
    "updated_at": "2025-11-21T08:27:10.241Z",
    "task_id": "d4g24nep2jvh04o9uoh0",
    "user_id": "wfi7wGPS4B4PdtTMox5Y",
    "status": "processing",
    "total": 2049,
    "success": 1024,
    "failure": 0
}

Provide a response indicating the task is completed and include the download URL for the results.

{
    "created_at": "2025-11-21T08:27:09.933Z",
    "updated_at": "2025-11-21T08:27:10.241Z",
    "task_id": "d4g24nep2jvh04o9uoh0",
    "user_id": "wfi7wGPS4B4PdtTMox5Y",
    "status": "exported",
    "total": 2049,
    "success": 2049,
    "failure": 0,
    "result_url": "https://wapic.s3.ap-southeast-1.amazonaws.com/externalcheck/d4g24nep2jvh04o9uoh0/d4g24nep2jvh04o9uoh0.zip?X-Amz-Algorithm=AWS4-HMAC-SHA256..."
}

Upload file request url

POST https://api.checknumber.ai/v1/tasks

Upload file request parameters

Parameter	Description
file	file, Upload file, each line should contain one phone number in E.164 format
task_type	string, Task type, set to “microsoft”

Check task status request url

POST https://api.checknumber.ai/v1/gettasks

Check task status request parameters

Parameter	Description
task_id	string, Task ID returned from task creation

Result Fields

Field	Description	Example
Number	Phone number in E.164 format	+12025551234
microsoft	Whether number is registered with Microsoft	yes, no

Response Format

Field	Description
created_at	Timestamp when task was created
updated_at	Timestamp of last task status update
task_id	Unique task identifier
user_id	ID of user
status	Task status: pending: Queued and waiting processing: Currently processing exported: Results available for download
total	Total phone numbers processed
success	Numbers successfully verified
failure	Numbers that failed processing
result_url	(Optional) Download URL for results when status is exported

Status Codes

Status	Description
200	charge, Request successful, task created or status retrieved
400	free, Bad request, invalid parameters or file format
500	free, Internal server error, retry later