收據僅僅是一張紙。

https://www.keepertax.com/posts/irs-audit-no-receipts

What to do if you don't have receipts

Facing an IRS tax audit with missing receipts? The IRS often allows self-employed taxpayers to substantiate expenses throgh other means

The IRS will only require that you provide evidence that you claimed valid business expense deductions during the audit process. Therefore, if you have lost your receipts, you only be required to recreate a history of your business expenses at that time.

隻要有手機截屏，打到法院都不用怕。