To find your balance at the end of a given month, you can use the filters in the Payments > Transactions tab. This workflow only works when you have received a payout for all transactions in the month you want the balance for.
Step 1
Start by filtering on what has been captured in the month you want the end-of-the-month balance for. Select More > Capture date > Select the entire month you want the balance for and select Apply.
Step 2
Select the payout date the same way as in the previous step. Remember to select the date range in the month after the month you want the balance for.
Step 3
When you've selected your capture date and payout date filters, select Export.
Choose CSV as the format, and Custom for date range, then Export again.
The sum of the transactions you export is your end-of-the-month-balance. This will need to be summarized manually in Excel or similar tools that can read CSV files.