<p>Updates a budget. You can change every part of a budget except for the <code>budgetName</code> and the <code>calculatedSpend</code>. When you modify a budget, the <code>calculatedSpend</code> drops to zero until Amazon Web Services has new usage data to use for forecasting.</p> <important> <p>Only one of <code>BudgetLimit</code> or <code>PlannedBudgetLimits</code> can be present in the syntax at one time. Use the syntax that matches your case. The Request Syntax section shows the <code>BudgetLimit</code> syntax. For <code>PlannedBudgetLimits</code>, see the <a href="https://docs.aws.amazon.com/aws-cost-management/latest/APIReference/API_budgets_UpdateBudget.html#API_UpdateBudget_Examples">Examples</a> section. </p> </important>

{
  "success": true,
  "data": {
    "id": "abc123",
    "created_at": "2025-01-01T00:00:00Z"
  }
}

{
  "success": false,
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid request parameters"
  }
}