Accounts are a tricky part of Bustle and at this point we're unable to reverse an assignment once it's been placed onto an account. This is why we pop up a warning and have a confirmation step when assigning.
But despite the best of care being taken when assigning to an account, mistakes can happen.
Assigned a tab incorrectly
While we are unable to remove the assignment, there is a way for you to correct the account financially.
Open the account on the iPad app (Settings > Accounts & Vouchers). Press the Pay Account button. Press Partial and key in the amount in error, then press the Clear Balance button.
This removes the amount from the account (and Bustle) so the order/tab will need to be created again if needed, and assigned correctly. NB: Your stock movement will be impacted as there is a double entry. This can't be changed.
Credited an account the wrong amount
This gets a little trickier. To fix this up on the account, you will need to create a new button for your menu on your Bustle Hub.
Set the sales price to be the amount you need to remove.
Name it whatever you like - "Account fixup"
Add the button to the menu, save.
On the Bustle iPad till app go to Settings > press Sync Menu
create a new order by adding the "Fixup" button to it.
Assign the order to the account to get it to the correct amount
Remove button from menu, delete the item and sync the menu on the iPad app again.
NB: This removes the extra amount from the account but expect your cash up to have a variance of the amount assigned incorrectly. This cannot be adjusted.