Checking your supermarket receipt for scan errors (Australia)

When receipt errors happen

Supermarket pricing systems are complex—half-price promotions, multi-buy tiers, member-only prices and weight-labelled items all interact. Errors at the register do occur, usually without any intent: a loyalty card not scanning, a special that expired mid-week but stayed on the shelf, or a weight label read incorrectly at the deli counter.

A quick review before you leave the carpark catches most of these. It takes about ninety seconds on a typical shop.

This is general shopping information, not consumer law advice. For formal disputes, check the retailer's own process or contact a relevant consumer authority.

Common things to look for

• Half-price specials charged at full price — often because the loyalty card was not scanned or the promotion required app activation.
• Multi-buy discounts not applied — "3 for $X" sometimes fails to kick in if items ring up individually.
• Online substitutions at unexpected prices — a different brand or pack size than you chose can change the line total. See our guide on Click & Collect and delivery.
• Weighted items — deli or butcher-counter items with printed weight labels can occasionally be keyed incorrectly.

A simple review process

1. Glance at your subtotal while still at the register—if it feels significantly higher than usual, flag it before you tap.
2. Step aside and skim through the receipt for any lines you expected to be on special showing full price.
3. If something looks wrong, head back to the service desk promptly—staff can usually resolve straightforward scan errors quickly.

Loyalty prices and what you actually paid

Member-only pricing means the price you saw advertised may not be what you paid if the card did not register. Our guide on loyalty programs and checkout price explains how member pricing works at the major chains.

Does price checking beforehand help?

Looking up staples on TrolleyChecker before you shop gives you a sense of what to expect at the register—which makes genuine errors easier to spot. It does not audit your receipt, but it reduces the chance of being caught off guard by a price that looks wrong when it is actually correct.

Honest limits

Not every price discrepancy is an error—promotions change mid-week and your local store may not match a national catalogue exactly. If a receipt line does not match your expectation, check the current shelf ticket before raising it with staff.