Choose whose wallet pays for this domain

PUT

/domains/{domain}/billing-member

curl --request PUT \
  --url https://api.nsin.ir/domains/example.com/billing-member \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{ "user_id": 1 }'

• Production

Nominates the member whose wallet is charged for this domain — automatic renewals and interactive purchases alike — or clears the nomination with user_id: null so the owner pays again.

Owner only (platform support aside). This is deliberately not gated on domain.settings: a member with the admin role holds that permission, and an admin member must not be able to point the bill at somebody else on a domain they do not own.

The nominee must already hold an accepted membership on this domain. A pending invitation is not one — it grants nothing until it is accepted, and nominating against it would let an owner charge someone who never joined.

There is no consent step and no pending state: the nomination is in force the moment it is written, and the nominee is notified immediately. Their escape hatch is leaving the domain. Use GET /domains/{domain}/payer to show who pays, and what they have, before a purchase.

Authorizations

• bearerAuth
• apiKeyAuth

Parameters

Path Parameters

domain

required

string

The domain name (for example example.com) — not a numeric id.

Example

example.com

Request Body ^required

Media type application/json

object

user_id

The member’s user id, from GET /domains/{domain}/members. null, 0 or the owner’s own id all clear the nomination — the owner paying is the absence of a nomination, not one of its own.

integer | null

Example ^generated

{
  "user_id": 1
}

Responses

200

The payer after the change. Always populated: with no nomination in force it describes the owner.

Media type application/json

object

billing_member

Whose wallet this domain’s charges come out of. Always populated — with no nomination in force it describes the owner.

object

user_id

integer

name

string

email

string

set_by

Who made the nomination. Absent when the owner pays.

integer

set_at

string format: date-time

is_owner

True when no nomination is in force and the domain owner pays. The owner being named explicitly is stored as no nomination, so this never disagrees with ownership.

boolean

Example ^generated

{
  "billing_member": {
    "user_id": 1,
    "name": "example",
    "email": "example",
    "set_by": 1,
    "set_at": "2026-04-15T12:00:00Z",
    "is_owner": true
  }
}

400

Malformed body, or the nominee has no accepted membership on this domain (code: not_a_member).

Media type application/json

object

error

required

Human-readable description of what went wrong.

string

code

Present when the nominee has no accepted membership on this domain — so a client can offer “invite them first” instead of just printing the message.

string

Allowed values: not_a_member

Examples

Example notAMember

{
  "error": "that person must accept the domain invitation before they can be set as the payer",
  "code": "not_a_member"
}

401

Missing, malformed, revoked or expired API key — or the owning account is inactive.

Media type application/json

The single error shape used by every endpoint.

object

error

required

Human-readable description of what went wrong.

string

Examples

Example invalidKey

{
  "error": "invalid API key"
}

403

The key is read-only, or you are a member of this domain but not its owner.

Media type application/json

The single error shape used by every endpoint.

object

error

required

Human-readable description of what went wrong.

string

Examples

Example notOwner

{
  "error": "only the domain owner can choose who pays for this domain"
}

404

No such domain, or it is not visible to this account. Domains you cannot access are reported as not found rather than forbidden.

Media type application/json

The single error shape used by every endpoint.

object

error

required

Human-readable description of what went wrong.

string

Example

{
  "error": "read-only API key"
}

429

The key exceeded its request budget (300 requests per minute by default).

Media type application/json

The single error shape used by every endpoint.

object

error

required

Human-readable description of what went wrong.

string

Examples

Example limited

{
  "error": "rate limit exceeded"
}