Use QuickBooks Online Classes and Locations for segment tracking on transactions via API

In-depth guide

Steps

1. Confirm Class tracking and Location tracking are enabled in QBO Company Settings > Advanced; they can be enabled independently
2. Create Class records via POST /v3/company/{realmId}/class with 'Name' and optionally 'ParentRef' for sub-classes
3. Create Department (Location) records via POST /v3/company/{realmId}/department with 'Name'
4. When creating a transaction, set 'ClassRef' and/or 'DepartmentRef' at the header level or on individual Line objects depending on the feature's 'per-transaction' vs 'per-line' setting in QBO
5. Retrieve class and location breakdowns by querying the QBO reports API for P&L by Class or Location (/v3/company/{realmId}/reports/ProfitAndLoss?summarize_column_by=Classes)
6. List all classes via SELECT * FROM Class and departments via SELECT * FROM Department using the query endpoint