A receipt is proof that an expense happened, when, to whom, and for how much. Tax authorities expect you to be able to produce that proof for business deductions, and the common failure is not losing receipts but never connecting them to the transaction they support. The fix is to make the receipt part of the entry the moment you record it.
Capture at the point of purchase
Photograph paper receipts with your phone before they fade or disappear; thermal paper can be unreadable within months. For online purchases, save the confirmation email or invoice as a PDF. Either way, attach the file to the transaction in your ledger right then, with the vendor, date, amount, and category filled in. A receipt that sits in a camera roll is a receipt you will have to hunt for later.
If your bookkeeping tool can read the receipt and fill in the entry for you, use it, but check the result. Totals that include tips, foreign currency, or split payments are where automated reading most often needs a correction.
What the receipt has to show
A usable receipt shows the vendor name, the date, the amount, and what was bought. Card statements alone usually do not satisfy the last requirement, which is why a statement line is not a substitute for the itemized receipt. For meals and travel, add a note about the business purpose and who was present; the receipt proves the cost, the note proves it was business.
For recurring digital charges, one invoice per billing period is ideal, but a single annual statement from the vendor that lists each charge is generally acceptable. For small cash purchases without a receipt, a dated note with the amount and purpose is better than nothing, kept to a minimum.
Storage, retention, and privacy
Keep receipts for as long as the return they support can be examined, which is typically several years after filing and longer for assets that are depreciated over time. Digital copies are accepted as long as they are legible and complete. Store them where they are backed up and where you can export everything at once if you change tools or accountants.
Receipts sometimes carry more than you need: full card numbers, home addresses, loyalty identifiers. Trim or redact what is not needed before uploading, and keep business records in a workspace separate from personal files so that sharing with an accountant never exposes the wrong thing.
A monthly check that takes ten minutes
Once a month, list the expenses without an attached receipt and resolve each one: find the receipt, download the invoice, or write the note that explains why none exists. Then review the entries you entered in a hurry and confirm the category and business-use percentage. Doing this monthly means year end is an export, not a reconstruction.
Retention periods and documentation requirements vary by jurisdiction and by the type of expense. Ask your tax preparer what applies to you.