---
title: "Update Anchor"
method: PATCH
path: "/2026-04/subscription/{subscriptionId}/anchor"
---

# Update Anchor

`PATCH /2026-04/subscription/{subscriptionId}/anchor`

## Request

- Base URL: `https://api.loopsubscriptions.com/admin`
- URL: `https://api.loopsubscriptions.com/admin/2026-04/subscription/{subscriptionId}/anchor`
- Auth: API key in header `X-Loop-Token`

This endpoint allows you to update the billing anchor on an existing subscription contract

## Path parameters

- `subscriptionId` string, required

## Request body

- object
  - `anchorType` 'WEEKDAY' | 'MONTHDAY' | 'YEARDAY', required: The subscription's current billing cycle type: WEEKDAY, MONTHDAY, or YEARDAY. Pass null (small-case) to remove the existing anchor.
  - `anchorDay` integer, required: The day within the billing cycle the subscription should be anchored to
  - `anchorMonth` integer, required: The month of the year to anchor to (used only when anchorType is YEARDAY). For MONTHLY and WEEKLY anchorType, pass any number greater than 0

## Response `200`

- object
  - `success` boolean: Indicates whether the request was processed successfully.
  - `message` string: A message describing the result of the request.
  - `data` string: Returns null for this endpoint as no additional data is returned upon a successful update.
  - `code` string: The response code indicating the outcome of the request.
  - `pageInfo` string: Pagination metadata. Returns null for this endpoint as pagination is not applicable.

---

[API](https://skmtc.dev/loopwork/apis/loop-admin.md) - [All operations](https://skmtc.dev/loopwork/apis/loop-admin/llms.txt) - [OpenAPI document](https://skmtc.dev/loopwork/apis/loop-admin/revisions/1eaf81bcb1ea?raw)