Once a recap is saved in Fully Fixed status, it can still be edited for up to 72 working hours following it being saved in that status.

After this time, it is not possible to make changes.  The recap is locked from editing.  Any changes that need to be applied must be done so in the form of an Addendum.

This is not always appropriate based on the change needed.

An alternative is to make a copy of the recap, ensure the recap date is entered as per the original fixture, make the changes, share with the appropriate parties and then save as 'Fully Fixed'.  Ensure you change the status of the original to 'Cancelled' to avoid confusion and avoid double charging for the same fixture.