Explaining a budget variance
Listen to this lesson
Nigerian voice narration
Fictional training case. Q3 actuals for your agency are ₦18.4m above budget on overheads, and the Accounting Officer wants an explanation by close of business today. This lesson shows how to use AI to rank variances quickly and draft a management-ready narrative. Work through the example, identify the evidence needed and practise the method with cleared or synthetic inputs. Any additional figures in the explanation are separate practice examples, not claimed rows in a downloadable file.
Worked example
Fatai downloads the sample budget-vs-actual sheet showing ₦18.4m total overhead overspend. He pastes the table into AI and asks it to list the top 3 variances by Naira amount and by percentage, ranked. The AI flags Fuel and Lubricants as the largest single-line overspend at ₦9.2m — but before trusting that number, Fatai re-checks it in Excel himself and confirms it matches. He then asks AI to draft a 150-word variance note covering cause, impact and a recommended control, keeping every figure exactly as it appears in his verified spreadsheet rather than any number the AI mentioned independently.
The method
Paste the full budget-vs-actual table and explicitly ask for variances ranked by both amount and percentage, since the biggest Naira variance is not always the biggest percentage variance. Independently verify every ranked figure in Excel before it appears in a management note — AI can make arithmetic errors on large tables. Draft the explanatory narrative only after the numbers are confirmed, never before.
Worked practice and common mistakes
With budget ₦40m and actual ₦46m, the difference is ₦6m and the percentage is 15%. Rank amount and percentage separately. If budget is zero, this percentage is undefined: report the amount and mark the percentage not applicable. A suspected driver belongs in a confirmation list rather than a definitive explanation unsupported by vouchers or source records.
Review before using the result
AI ranks variances quickly but your spreadsheet is the only source of truth for final figures. Variance percentage is (Actual − Budget) ÷ Budget × 100. Draft the narrative last, after verification, and keep AI drafting — never approving.
Your workplace practice
Use the recommended free assistant with this lesson's fictional example. Here is a budget vs actual table in Naira. List the top 3 variances by amount and percent, then draft a 150-word variance note for the Accounting Officer. Keep a copy of the input and draft. Compare the result with the verification steps above, record any correction, and retain placeholders where evidence is missing. The expected result is a checked draft for human review, not an automatically approved decision. Course examples and practice responses are fictional; amounts, dates, rules and thresholds are not official guidance or supplier quotations.
Open ChatGPT (free tier) and paste this prompt there. Explains variances in plain English and drafts the narrative quickly.
Here is a budget vs actual table in Naira. List the top 3 variances by amount and percent, then draft a 150-word variance note for the Accounting Officer.
Why this tool: Explains variances in plain English and drafts the narrative quickly.
Hit a free limit? Switch to ChatGPT or Gemini and continue — the prompt works in any assistant.