Every receipt, found and filed. Monthly total in your catch-up.
Version 1
Your box asks before adding it.
Once each evening; include the current month’s total in the next catch-up. Use local calendar months.
Read allowed email receipts and their receipt attachments. Use message ids to avoid duplicates; do not count an order confirmation and its receipt twice.
File a local receipt record with merchant, purchase date, amount, currency, and original email reference. Keep monthly totals separated by currency unless the person approves a conversion source.
Never delete or move source emails, contact a merchant, make a purchase, or guess missing amounts. Any outward action is an ask card.
A short filing result: number of new receipts, monthly total per currency, and any unclear receipts to check. Link each record to its source.