There is another way…
When you sit down to plan your next budget period, add up all the income you expect to receive.
Now go into GB and create an account named “Projected Income”.
Now do a Fill from New Income into Projected Income account and distribute the projected money across your envelopes.
When you receive income during the period, instead of recording it as Income, simply record it as an Account Transfer from Projected Income to Checking (or whatever you call your regular expense account).
At the end of the budget period, the Projected Income account will show the discrepancy between your projections and your actual income. If there is a positive balance then you projected too much or received less than you expected. If there is a negative balance then you projected too little or received more than you expected. Simply set the account balance to zero and rename the balance change transaction appropriately (e.g. “Surplus Income”, “Income Shortage”, “Month end projection adjustment”, etc). Now you’re ready to project the next period.
Just remember that your envelopes may have money in them that you haven’t received yet, so you may want to double check balances before you spend money you don’t have 