---
title: "Create Regularization"
method: POST
path: "/api/v3/clients/{client_id}/regularization.json"
tags: ["Treasury"]
---

# Create Regularization

`POST /api/v3/clients/{client_id}/regularization.json`

Creates a new client’s regularization.

## Path parameters

- `client_id` string, required

## Query parameters

- `api_key` string, required

## Request body

- RegularizationRequest
  - `regularization` object, required
    - `value` number, required
    - `date` string, required
    - `observation` string, nullable

## Response `201`

SUCCESS

- RegularizationCreateResponse
  - `regularization` object
    - `id` integer
    - `number` string
    - `value` number
    - `date` string, date
    - `observation` string, nullable

## Other responses

- `401` — ACCESS DENIED
- `404` — NOT FOUND
- `422` — UNPROCESSABLE ENTITY

## Changes

- **2026-08-25** `5b82d4eb0d9f` — 2 breaking, 1 warning, 6 info
  - the `errors` response's property type/format changed from `object`/`` to `array`/`` for status `401`
  - the `regularization` response's property type/format changed from `array`/`` to `object`/`` for status `201`
  - removed the optional property `errors/error` from the response with the `401` status
  - the request property `regularization/observation` became nullable
  - …5 more

[Change history](https://skmtc.dev/invoicexpress/apis/invoicexpress-api/changes/api/v3/clients/:client_id/regularization.json/post.md)

---

[API](https://skmtc.dev/invoicexpress/apis/invoicexpress-api.md) · [All operations](https://skmtc.dev/invoicexpress/apis/invoicexpress-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/invoicexpress/invoicexpress-api/revisions/59bc808e8784/schema)