Add a brand document

POST/api/v1/sms/brands/{id}/documents

POST /sms/brands/{id}/documents

curl -X POST 'https://www.unitpost.com/api/v1/sms/brands/sms_123/documents' \
  -H 'Authorization: Bearer YOUR_API_KEY' \
  -H 'User-Agent: my-app/1.0' \
  -H 'Content-Type: application/json' \
  -d '{ }'

Response · 201

{
  "object": "sms_brand_document",
  "id": "id_123",
  "brand_id": "brand_123",
  "kind": "registration_certificate",
  "carrier": "string",
  "country": "string",
  "label": "string",
  "input": "file",
  "filename": "string",
  "content_type": "string",
  "size_bytes": 1,
  "text_value": "string",
  "created_at": "2026-01-01T00:00:00.000Z"
}

Add a document to the brand's library: a file kind takes file_id (Create a file, purpose sms_document), business_number takes text. A document in an occupied slot replaces the current one (kept only while a registration under review sent it). country makes it one country's own version of a shared document. The same checks as the dashboard (the slot's own file rule, a brand that isn't archived). Send an Idempotency-Key so a retry adds one document. Requires the sms:manage capability.

Parameters2 fields

Field	Type	Description
`id`required	string · path	—
`Idempotency-Key`	string · header	Any unique string (1–256 characters, e.g. a UUID). Retrying with the same key and the same body within 24 hours returns the first result instead of sending again; the same key with a different body is `409 invalid_idempotent_request`, and one still in flight is `409 concurrent_idempotent_requests`.

Request body5 fields

Field	Type	Description
`kind`required	enumregistration_certificate \| letter_of_authorization \| proof_of_sender_id_connection \| signatory_id \| emirates_id \| signatory_passport \| establishment_card \| power_of_attorney \| business_license \| tax_document \| regulatory_license \| carrier_registration_form \| opt_in_screenshot \| business_number	The document slot. File kinds: `registration_certificate`, `letter_of_authorization`, `proof_of_sender_id_connection`, `signatory_id`, `emirates_id`, `signatory_passport`, `establishment_card`, `power_of_attorney`, `business_license`, `tax_document`, `regulatory_license`, `carrier_registration_form`, `opt_in_screenshot`. Text kinds: `business_number`. A document in an occupied slot replaces the current one (the old one is kept only while a registration under review pinned it).
`carrier`	string	The slot's variant, for documents addressed to one carrier (a letter of authorization for `ooredoo`). A Sender ID refusal names it.
`country`	string	Make this one country's own version of a shared document (ADR-0115): it goes to that country only. Refused for a slot only one country reads.
`file_id`	string	A file kind: a file made with `POST /files`, purpose `sms_document` (PDF, PNG or JPEG, up to 3 MB; a slot can take less, e.g. Singapore's letter is a PNG up to 400 KB) or `sms_opt_in_evidence` for `opt_in_screenshot`.
`text`	string	A text kind (`business_number`).

Response · 201 fields13 fields

Field	Type	Description
`object`required	string	—
`id`required	string	—
`brand_id`required	string	—
`kind`required	enumregistration_certificate \| letter_of_authorization \| proof_of_sender_id_connection \| signatory_id \| emirates_id \| signatory_passport \| establishment_card \| power_of_attorney \| business_license \| tax_document \| regulatory_license \| carrier_registration_form \| opt_in_screenshot \| business_number	—
`carrier`required	string \| null	The slot's variant: which carrier or form a letter is addressed to (e.g. `ooredoo`), or null.
`country`required	string \| null	Set when this is one country's own version of a shared document (ADR-0115): it goes to that country only, in place of the shared file. Null for the shared file.
`label`required	string	What the document is, in words: "Letter of authorization — Ooredoo (Qatar)".
`input`required	enumfile \| text	—
`filename`required	string \| null	—
`content_type`required	string \| null	—
`size_bytes`required	integer \| null	—
`text_value`required	string \| null	`business_number` only.
`created_at`required	string	—

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Add a brand document

Add a brand document

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