Changing a budget amount for previous months
If you add a budget amount to a particular category or subcategory in Microsoft Money, you will see this budget amount reflected in the budget for future months. Microsoft Money will not change anything for previous month in the budget though, as these months are in the past and are no longer considered as changes you would want to make.
For example, if you had a regular tax bill of $100, then this changed to $120 for all future months, it doesn't make sense to change it for previous months as then you would be underbudget for those months. In some scenarios, it could make sense, and these are the ones you wish to address.
To change the budget for months that have already happened, then you will need a workaround. This workaround is to pretend it is the past, and reset the clock on your PC (don't do this with Microsoft Money running, and it wouldn't be recommended to try this on any trial version). Change the clock back to a date before the month in which you want to make the change.
When you restart Money, you can then enter the budget details, which will be used for "future" months - ie, those which you need the change to be applied to.
As usual with such a change, make a backup before you start (Article 94