Yes, there are two ways you can accomplish that. 

1) Use the Flat Fee plus charges Fee Arrangement when setting up the client. Keep the duration of Perpetual to have Timeslips charge it every time you run a bill for that client.

2 Create a Flat Fee &  Recurring slip for the $400. 

With a Recurring slip, it will be dated the day of the bill run each cycle.

Nancy Duhon, Esq.
Duhon Technology Solutions, LLC
Master Certified Consultant for Sage Timeslips
Providing individual Consultations and Third Party Remote Desktop Support - including older/unsupported versions.
404-325-9779
[email protected]

Thank you!