Thermal paper
Heat-sensitive paper used for most store receipts. The print can fade within months, especially with heat, light or friction.
In short
- Thermal receipts are printed by heat, with no ink, which is why they fade.
- A receipt that has faded blank cannot support a tax claim or a reimbursement.
- Scanning or capturing receipts at purchase is the reliable fix.
Thermal paper is coated with chemicals that darken when heated. Receipt printers use a heated print head instead of ink, which makes them cheap, fast and nearly maintenance-free. That is why almost every cash register, card terminal and parking machine uses it.
Why receipts fade
The same coating that reacts to the print head keeps reacting to its surroundings. Heat from a car dashboard, sunlight, friction in a wallet, contact with plastic sleeves and hand lotion all speed up fading. Some receipts are unreadable within a few months; stored well, others last several years. Few last the six years that Canadian tax rules generally require records to be kept.
Health and handling
Many thermal papers use bisphenol A (BPA) or a close substitute such as BPS as the developer. Both can transfer to skin with handling, which has led some retailers to switch to phenol-free paper and some jurisdictions to restrict BPA in receipts.
What to do about it
A faded receipt is a missing receipt. The practical answer is to capture the receipt when it is issued, either by photographing it at once or, better, receiving it digitally so there is no paper to fade. Tax authorities accept clear electronic copies in place of the paper original.
Worked example
A receipt found at audit time
During a review of 2023 expenses, a company pulls a $412 receipt for hotel furniture repairs from a filing box. The paper is almost blank: the total and date are gone. Without a legible copy, the expense and the $53.56 of HST claimed on it cannot be supported. A photo taken on the day it was issued would have settled it.