Negative Other Charge on Secondary Ledger
Setup an Other Charge that is associated with the Referral Fee expense account.
This should be setup with the same frequency as the Referral Fee is paid out. If this is paid daily, the Other Charge should be setup as Daily. If this is paid monthly, the Other Charge should be setup Monthly.
Create a second ledger for the Corporate Client receiving the Referral Fee. Select the Referral Fee Other Charge on this ledger. Make sure that the Rate is a negative amount. This will post as a discount on the invoice, reducing the revenue.
Since the Referral Fee is posted to an expense account, the ADR will not be affected since expenses are not included in ADR calculations. If this should be included in the ADR, including will reduce the ADR, the Referral Fee account should be included in the ADR accounts in Program Settings.
This will show on its own invoice, similar to a Credit Memo, and can be applied to any outstanding invoice.