After the initial Bulk Validation request is sent and the processing begins, the time needed to complete this processing can vary.

To return an update on how many IDs have been processed, use a GET operation and the following URL:

{service_url}/bulk`api/v3/tax_numbers/validate

where {service_url} is the URL of the service's environment.

You can also use this request to retrieve previously created results. To do so, you need to specify the request_id in the URL. For example, use a GET operation and the following URL:

https://tax-id-validator-bulk-api.sandbox.marketplace.taxamo.com/bulk/api/v3/tax_numbers/validate

Restrictions

The response returns up to 100 results per request.

Details

Type	Value
Endpoint	`/bulk/api/v3/tax_numbers/validate`
Method	GET

Response parameters

The following fields are returned in the response to this request:

Field	Description
`items.status`	This describes the status of the validation.
`items.status.request_id`	This ID represents the request to validate the Tax IDs.
`items.status.id`	This ID represents the validation result or status. You can use this to retrieve results with the Poll Last Seen Result request.
`items.status.output.buyer_tax_number_valid`	This Boolean indicates whether the Tax ID is valid or not.
`items.status.output.buyer_tax_number_format_valid`	This Boolean indicates whether the syntax of the Tax ID is valid or not.
`items.status.output.buyer_tax_number_Validation_info`	This field provides information about the status of the validation. For example, `tax-number-syntax-invalid` means that the Tax ID has failed the syntax check.
`items.status.output.buyer_tax_number_normalized`	This is a normalized version of the Tax ID.
`items.status.output.buyer_tax_service_cache_used`	This Boolean indicates whether the cache of Tax ID validation results was used or not.
`items.status.output.buyer_tax_service_cache_timestamp`	This shows the time when the cached result was saved in the cache.
`tax_number_service`	This specifies the service such as VIES that validated the Tax ID.

The response also contains the same output fields as any other Vertex Validator response. See Vertex Validator Output Schema.

Example

Request

The following is an example request:

`GET https://tax-id-validator-bulk-api.sandbox.marketplace.taxamo.com/bulk/api/v3/tax_numbers/validate`

Response

The following is an example response for the request:

{
    "items": [
        {
            "status": "processed",
            "request_id": "ANKpMhAXMAA=",
            "id": "CMGpMhACMAA=",
            "output": {
                "buyer_tax_number_valid": false,
                "buyer_tax_number_format_valid": false,
                "buyer_tax_number_validation_info": "tax-number-syntax-invalid"
            }
        },
        {
            "status": "processed",
            "request_id": "ANKpMhAYMAA=",
            "id": "CMGpMhAFMAA=", 
            "output": {
                "buyer_tax_number_valid": false,
                "buyer_tax_number_format_valid": true,
                "buyer_tax_number_validation_info": "tax-number-invalid-according-to-external-service",
                "buyer_tax_number_normalized": "111111111",
                "buyer_tax_number_service_cache_used": true,
                "buyer_tax_number_service_cache_timestamp": "2025-08-20T15:07:34Z",
                "tax_number_service": "tax.service.gov.uk.api"
            }
        }
    ]
}