---
search:
  tags:
    - projects
    - PATCH
seo:
  description: >-
    Updates only the provided fields of an existing… Reference for the PATCH
    /projects/{projectId}/interim-payments/{id} endpoint in the Leadtime Public
    API API.
sidebar:
  badge: PATCH
  label: Partially update interim payment
title: Partially update interim payment
type: openapi-operation
---
Updates only the provided fields of an existing interim payment. Fields not included in the request remain unchanged.

**How partial updates work:**
- Only fields included in the request body are updated
- Omitted fields retain their current values
- Description can be updated with new HTML or Markdown content
- Sort order is not changed (use the sort endpoint to reorder payments)

**Updatable fields:**
- **title**: Update the payment label
- **description**: Update payment notes (HTML or Markdown format)
- **amount**: Change the payment amount (must be positive, minimum 0.01)

**Important restrictions:**
- Cannot update the isBilled status (this is managed automatically by the invoicing system)
- Cannot change the project ID (payment is tied to the project)
- Cannot update creation date or user ID

**Validation:**
- If amount is provided, it must be a positive number (minimum 0.01)
- If title is provided, it cannot be empty
- Payment must exist and belong to the specified project

**Permissions:** Requires Projects.edit permission

<Operation source="api-reference" id="projectinterimpaymentscontroller-patchinterimpayment" />