Why isn't the allowance capping at the right time?
Example:
You're paying a Crew member a weekly 'Box rental' allowance (for use of their tools of trade). When using Timecards in Engine (using Timecard Standard or Premium modules only), the allowance payments will cap (stop being paid) when the cap is reached (the cap must be specified in their Offer, e.g. at 50% of the insurance-replacement value of the tools).
However, your project started paying this Crew member their allowance prior to Timecards being used in Engine; obviously Engine doesn't know how much you've paid, but someone with Accounts Admin or Accounts Controller admin rights is able to edit the 'Paid so far' value for said Crew member:
Click Timecards > Approve tab
Navigate to the week of that Crew member's start date
Click on Crew member name (to go to 'Crew View')
Scroll to beneath the days
Click 'Paid so far'
Edit the value accordingly (i.e. to the amount already paid in reality by the end of the previous working week)
Then click 'Save'
The amount paid so far in timecards for subsequent weeks will now show correctly, and also cap on the week you expect.