According to the game's mechanics, each character can carry a maximum of 40,000 caps. Additionally, each account can have up to 5 characters. If you require more than 40,000 caps, you must utilize additional characters or spend some caps beforehand. It's important to note that holding excess caps is against the game's rules, and Bethesda will remove any excess caps, with the buyer bearing the loss.

Trading Procedure:

When conducting a face-to-face trade in-game, please list items equivalent to the number of caps you've purchased or 40,000 caps if the order exceeds this amount. For orders exceeding 40,000 caps, multiple trades may be necessary to deliver all the caps.