BillKit/Docs Console
Customers

Set customer VAT number

Record a business customer's VAT registration number and check it.

POST/v1/customers/{customer_id}/vat_number
Operation set_customer_vat_number · Scope customers:write · Spec snapshot 2026-09-13

Parameters

ParameterDescription
customer_idstring · pathrequiredNo description in the spec.
country_codestring | nulloptionalAt most 2 characters.
vat_numberstring | nulloptionalAt most 64 characters.

Returns

Returns a CustomerResponse object.

Errors

Status Cause
401 Missing or invalid API key.
403 Key is missing the customers:write scope.
404 No such object, or it belongs to the other mode.
422 Validation Error
429 Rate limited. Back off and retry.
Request · curl 
curl -X POST https://api.billkit.eu/v1/customers/cus_9XKp2vQ1/vat_number \
  -H "Authorization: Bearer $BILLKIT_SECRET_KEY" \
  -H "Content-Type: application/json" \
  -d '{}'
Request body · every field 
{
  "country_code": "NL",
  "vat_number": "string"
}
Response · 200 OK 
{
  "country_code": "NL",
  "created": 1789392000,
  "email": "ada@example.com",
  "id": "cus_9XKp2vQ1",
  "livemode": false,
  "metadata": {
    "key": "value"
  },
  "name": "Ada Lovelace",
  "object": "customer",
  "provisional": false,
  "stats": {
    "currency": "EUR",
    "lifetime_cents": 1900,
    "object": "customer.stats",
    "subscription_count": 0
  },
  "test_clock": "string",
  "vat_number": "string",
  "vat_number_validated": false
}