type: string
enum:
  - EXPENSE
  - REFUND
  - CASHBACK
  - MAIN
  - CORRECTION
  - CREDIT_NOTE
  - UNKNOWN_DEFAULT_OPEN_API
description: |
  Subtype of the expense.

  **Subtypes:**
  - `EXPENSE`: Standard expense
  - `REFUND`: A returned-funds entry (merchant refund or returned transaction).
  - `CASHBACK`: Cashback or reward entries associated with card flows
  - `MAIN`: Main expense entry
  - `CORRECTION`: Corrective entry for adjustments
  - `CREDIT_NOTE`: A supplier credit (credit note) applied against an invoice
  - `UNKNOWN_DEFAULT_OPEN_API`: Unknown subtype (fallback for future subtypes)
example: "EXPENSE"