The Spending Plan does not currently offer the ability to roll over leftover funds from one month to another. However, you can set a custom Income total for your Spending Plans to include any additional amounts.
To set a custom Income amount in your Spending Plan, follow the below steps:
Hover over the menu on the left-hand side and select Spending Plan.
In the Income section, click the three dots on the right-hand side.
Select Set Custom Amount.
Enter the new Income amount and click Set Amount.