August 24, 2026

Get and Update a Single Estimate Summary

Two new endpoints work with a single estimate summary on a work item, addressed by its EstimateSummaryKey.

GET /v3/WorkItems/{WorkItemKey}/EstimateSummaries/{EstimateSummaryKey} returns one estimate summary, rather than the full list GET /v3/EstimateSummaries/{WorkItemKey} returns.

An EstimateSummaryKey starting with 0- represents time recorded against a task with no estimate assigned, rather than an actual estimate — these can be retrieved but not updated. Assign an estimate to the task in Karbon first.

GET /v3/WorkItems/4jgPTtcXxwC2/EstimateSummaries/160F79F6-E650-40C3-8BD9-F70C287B7476-0

{
  "EstimateSummaryKey": "160F79F6-E650-40C3-8BD9-F70C287B7476-0",
  "UserKey": "RXq4mB32PXg",
  "RoleKey": "qTLmJpG85Ng",
  "RoleName": "Accountant",
  "TaskTypeKey": "3h5Tbh9GgLs7",
  "TaskTypeName": "Admin",
  "EstimateMinutes": 60,
  "HourlyRate": 150,
  "ActualMinutes": 45,
  "EstimateAmount": 150
}

PATCH on the same path updates the estimate. Only EstimateMinutes, EstimateAmount and HourlyRate can be patched, and each is optional — send only the fields you want to change.

PATCH /v3/WorkItems/4jgPTtcXxwC2/EstimateSummaries/160F79F6-E650-40C3-8BD9-F70C287B7476-0

{
  "EstimateAmount": 250
}

Whether an estimate is budgeted by time or by amount is a firm-level setting, so exactly one of EstimateMinutes and EstimateAmount applies to any given estimate — supplying both is rejected, and the one that doesn’t apply can’t be set. EstimateMinutes accepts 0 to 599,999,940, and EstimateAmount and HourlyRate each accept 0 to 99,999,999.

A successful update returns 204 No Content.

Changing HourlyRate can reissue the EstimateSummaryKey. The response always includes an OData-EntityId HTTP header with the estimate summary’s location after the update — use that URL for subsequent requests rather than the key you sent, since it may no longer resolve.

odata-entityid: https://api.karbonhq.com/v3/WorkItems/4jgPTtcXxwC2/EstimateSummaries/98f400ba-888f-4f12-b59b-baefa7db99b3-0

An update is rejected with 422 Unprocessable Entity if the work item is completed, the change is blocked by the firm’s WIP lock date, rate plans aren’t enabled for the firm, or the estimate can’t hold the field supplied (for example, setting HourlyRate on a non-billable estimate).