Source: 'User's Guide - Fiduciary' accessible via the Help menu of Para-Maître/ Online Manuals / Modules / Fiduciary.

CANCELLATION OF A TRANSACTION (REC or DEB)
1. Pull down the menu "Accounting/Transactions/Transaction Entry".
2. Fill in the Financial Institution and Bank Account fields.
3. Click on the POLL icon or press the (F11) key on the keyboard to
return to the query mode.
4. Enter the search criteria to find the transaction to be reversed such as type of transaction, date, amount, etc.
5. Start the search by clicking on the PLAY icon or by
pressing the (F12) key on the keyboard.
6. Click on the button to access the Reversal of Receipt or
Disbursement window depending on the type of transaction you are looking for.

7. Enter the date of cancellation and the reason.

Note that you cannot reverse a transaction in a reconciled period.

Before cancelling a recipe, make sure that the receipt has been printed, it will be impossible to do so when the transaction is cancelled.