Section 01

A budget is only useful if someone notices when it is being missed. Gemini can help you build that early warning.

Most budget overspends are not discovered until month-end, when it is too late to do much about them. The figures usually exist in a spreadsheet well before that point — what is often missing is someone reviewing them regularly and flagging the lines that need attention.

Gemini can help close that gap. Used alongside a budget tracking sheet in Google Sheets, it can review spend-to-date against budget, flag the lines that are over or trending over, and draft short messages to send to the relevant budget holder — turning a sheet full of numbers into a short, actionable list.

Key insight: Gemini does not monitor your spreadsheet automatically or send alerts on its own. You bring it the current figures, and it helps you spot the lines that need attention and draft the message to the budget holder.

Flag overspend lines

Review a budget vs actual table and identify which lines are over budget or trending that way.

Draft alert messages

Turn a flagged budget line into a short, clear message ready to send to the budget holder.

Spot trends early

Compare run-rate against full-year budget to highlight lines likely to overspend before they do.

Without Gemini

Scroll through a long budget tracking sheet manually, trying to spot which of dozens of lines are running over — often only noticed once month-end reports are produced.

With Gemini

Share the current budget vs actual table and ask Gemini to list the lines that are over budget or on track to be, ranked by the size of the variance — ready for a quick review.

Gemini works from the figures in your sheet, so a clear, consistent tracking sheet makes the difference between a useful review and a confusing one.

Suggested columns for a budget tracking sheet: Department or cost line, Annual budget, Spend to date, Months elapsed, Expected spend to date (budget ÷ 12 × months elapsed), Variance (spend to date − expected spend to date), Budget holder.

Before asking Gemini to review the sheet

Make sure spend-to-date figures are up to date as of the same date for every line

Add a column for the budget holder's name so Gemini can address them directly in drafts

Decide on a variance threshold (e.g. lines more than 10% over expected spend) for Gemini to flag

Remove or hide any unrelated tabs or notes so Gemini only sees the relevant table

On track

Spend to date is at or below the expected run-rate for the period — no action needed, but worth noting in the summary for completeness.

Watch

Spend is close to the expected run-rate, within your chosen threshold — Gemini can flag these as lines to keep an eye on next month.

Over budget

Spend to date already exceeds the expected run-rate beyond your threshold — these are the lines Gemini should prioritise for an alert message.

These prompts help Gemini turn a budget tracking sheet into a short list of lines to review and draft messages for the relevant budget holders.

Prompt 1 — Flag budget lines that need attention

Act as a finance assistant. I am sharing a budget tracking table with columns for Department, Annual Budget, Spend to Date, Months Elapsed, Expected Spend to Date and Variance. Review the table and: - List the lines where spend to date is more than 10% above the expected spend to date - Sort them by the size of the variance, largest first - For each, state the department, the variance in both amount and percentage, and whether it is "Over budget" or "Watch" based on the threshold above If no lines exceed the threshold, say so clearly rather than listing lines that do not qualify.

Prompt 2 — Draft an alert message for a budget holder

Act as a finance business partner. I need a short message to send to a budget holder about their department's spend. Department: [Department name] Budget holder: [Name] Annual budget: [Amount] Spend to date: [Amount] Expected spend to date: [Amount] Variance: [Amount and percentage] Write a brief, polite message (3-4 sentences) that states the current position factually, asks the budget holder to review the figures, and invites them to share any context for the variance. Do not assume a cause for the overspend.

Important: Gemini reviews the figures you share at the moment you share them — it does not run automatically or watch your sheet in real time. For this to work as an early-warning system, the review needs to become a regular habit, such as weekly or monthly.