Preserve the original plan

Do not overwrite the budgeted amount with actual spending at the end of the month. Keep both columns and calculate the difference. The original forecast is useful evidence about what you expected, even when it turned out to be wrong.

For a hypothetical category budgeted at 200 and spent at 260, the difference is 60. That number does not explain the cause. A higher price, a one-off purchase, an omitted bill and a recording mistake all call for different responses.

Sort the causes

Check errors first: duplicate transactions, transfers counted as purchases, refunds recorded twice or a bill assigned to the wrong period. Next, identify costs that were known but missing from the plan. These suggest an incomplete forecast rather than an unexpected event.

Then separate temporary changes from continuing ones. If 45 of the 60 difference paid for a one-off visit and 15 reflected a continuing fare increase, next month's ordinary allowance may need the additional 15. The visit can remain separately identified without becoming an automatic monthly cost.

Finally, consider choices made during the month. Perhaps a purchase was worthwhile but took money intended for something else. Record that trade-off plainly. A budget can change, but the other purpose must be updated so the same cash is not promised twice.

Close the cash consequences

An overspend may have reduced savings, increased a card balance or used money reserved for a later bill. Identify which happened. Simply raising next month's category does not repair the existing shortfall.

If the difference was covered from another category, reduce that category's remaining assignment. If it created borrowing, keep the resulting payment obligation visible. Where essential bills are at risk, address the actual payment issue rather than concentrating only on category labels.

Choose a small number of changes supported by the evidence: a missing annual-cost line, a revised travel estimate or an earlier balance check. Keep a note explaining each change. The next review can then test whether the adjustment helped, rather than repeating a general promise to spend less without identifying what was wrong.