Guide

How to reconcile your ad budget at month-end

Month-end is where most of the value leaks out of a marketing budget. Actuals come in, someone exports them into a spreadsheet, wrestles the formulas, chases the variance, and rebuilds next month from a blank sheet. It takes hours, and surplus quietly disappears in the process.

It doesn't have to. Reconciliation is a short, repeatable discipline — and done well, it pays off twice: a clean close, and recovered budget. Here's the method.

The steps

1. 1

   Lock the month

   Once final spend has landed, freeze the month. No more edits to the past — it becomes the record you reconcile against. Locking is what makes the numbers trustworthy instead of a moving target.

2. 2

   Pull actuals per channel

   Bring in what each channel actually spent — from the platforms or your source of truth. Reconcile per channel, not just in aggregate, so you can see exactly where the plan and reality diverged.

3. 3

   Calculate the variance

   For each channel, compare budget to actual. Note the gap in dollars and as a percentage. This is your honest scorecard — over-spenders and under-spenders both matter.

4. 4

   Decide what to do with surplus

   Underspend is not "saved" — it is at risk of vanishing at the close. Decide deliberately: roll it forward to next month, reallocate it to a channel that can use it, or release it. A decision, never a default.

5. 5

   Carry budgets forward

   Start next month set up — budgets in place and surplus allocated — instead of rebuilding from scratch. The best reconciliation makes next month's pacing a running start.

6. 6

   Keep an audit trail

   Record every change as a new entry, never an overwrite. "Why is this budget what it is?" should always have an answer. An append-only ledger is what turns reconciliation from a guess into a record.