At least 3 years for USA residents. According to the Internal Revenue Service (IRS), an individual or company is required to keep an invoice under the following circumstances:
- 4 years for invoices related to the payment of employees. The 4-year period begins after the date the tax is due or is paid, whichever is later;
- 6 years for invoices that are not reported on your income taxes and represent more than 25% of gross income;
- 7 years if filed the invoices are related to a claim for a loss from worthless securities or bad debt deduction; and
- Indefinitely if the invoice was made in a tax year where no filing was made or if a fraudulent return was filed.