IIRC, the only requirement is that there be a copy of the most recent
W&B calculation following any changes to the aircraft.

Arne wrote:
In USA, if you are flying under Part 91 of the Federal Aviation Regulations
(FARs).
Are you required to perform weight and balance checks before every flight?
And if so, are you required to document it? Can the FAA show up on the ramp
asking you to show the weight and balance calculation?