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Catch overcharges before you pay an event bill

Keep agreed supplier prices in a sheet and get each invoice checked against them, with any extra or wrong charges listed before you approve.

Event plannerIntermediate30 minAI assistantGmailGoogle Sheets

When to use it

Whenever a supplier invoice arrives

Record what you agreed
Make a Google Sheet for the event with a row per supplier: what was booked, agreed price, quantities, extras allowed, deposit paid and payment terms. Fill it as you sign contracts.
Label invoices as they arrive
Set a Gmail filter so emails with 'invoice' from your suppliers get an event label. In Outlook, use a rule to move them to a folder.
Check each invoice
Open the invoice and paste its lines, plus that supplier's row from your sheet, into your AI assistant with this prompt.
Prompt to copyCompare this supplier invoice with what we agreed. Agreed terms: [paste row from sheet, incl. contract notes]. Final numbers on the day: [e.g. 118 guests, 2 extra hours AV]. Invoice: [paste invoice lines]. Give me a table: line item, invoiced amount, agreed amount, difference, and status (matches / extra / wrong / not agreed). Then list: any charges that need a question, deposits that should have been deducted, and maths errors. End with a short, polite email to the supplier asking about the items that don't match.
Query or approve
Send the query email if needed, or mark the invoice approved in your sheet with the date. Keep notes of any agreed changes.