1. Purchase Order Reference: Include when client has provided a PO number or when required by client's procurement process

2. Project Reference: Add when services relate to a specific project or contract reference

3. Timesheet Details: Detailed breakdown of daily work hours when required by client

4. Currency Conversion: Include when invoice needs to show equivalent amounts in other currencies

5. Special Notes: Any special payment instructions or client-specific requirements

6. Late Payment Terms: Include when specific late payment penalties or interest charges apply

1. Timesheet: Detailed breakdown of hours worked, including dates, times, and activities

2. Service Details: Detailed description of services provided when too lengthy for main invoice

3. Rate Card: Breakdown of different hourly rates if multiple rates apply

4. Previous Balance Statement: Statement of any previous unpaid invoices or running balance if part of ongoing services