How do I change the opening balance on my accounts?

MoBill calculates the Opening Balance automatically and does not keep any record which can be updated. To adjust the opening balance, you have to add either a bill for debit balance or an income for credit balance on the first day of your very first period with the repeat is None, and then you need to mark it as Paid (or Received for income). You can type some meaningful description such as Account Opening in the description to make it distinguishable.

For example, if your opening balance is 100 USD then you need to add an income with 100 USD amount and Repeat is None. If your opening balance is -80 USD then you need to add a bill with 80 USD amount and Repeat is None.