3 For 2 offers at Tesco stores

Yes something similar happened to me in a different supermarket. I'd only purchased a few items amongst others were paper napkins on offer 3 for 2. I paid at the kiosk and as it was a small shopping basket I had a good idea of how much the bill would be. It seemed more than it should have been, so I accepted the receipt when it was offered. I left the kiosk and checked the offer, then pointed out to the cashier that I'd been charged separately for each pack of napkins. A supervisor was called to check and the bill was amended in my favour. All very amicably dealt with, but I do wonder if we are not meant to notice the extra charge.

Have you checked the bottom of the receipt? Items are added at normal price but then the offers are activated near the bottom.

Always, but always check your receipt.
Whilst still living in France, bought five items, the bill for which was way above what we were expecting. An item discounted to €1.32 went through the till as €13.21!!
Seems it is most often in the supermarket's favour

Yes a lot with Tesco’s, never under charged but always over charged! I now go through my receipts with an hawks eye to check for mistakes- they must love it when customers turn down their receipts 🙄

I never decline a receipt and I don’t leave the shop without checking it. I shop mainly in Tesco as it’s my closest supermarket. I’ve found errors in my receipts 3 times in the recent weeks. On one occasion the same item had been scanned twice and the other times items that were on offer but still scanned at full price.

I have the time to be vigilant and check my receipt. But I wonder how much extra profit supermarkets make from busy young families with a trolley load of groceries or someone rushing in and out on the way home from work and maybe not taking the time to check. An overcharged pound or 2 could easily go unnoticed on a full trolley.

Tanith it was not necessary to check the bottom of the receipt as the total amount charged made it clear that all three items were charged for, rather than just two as per the offer. I'm familiar with the layout of receipts with regards to offers.

Fair enough Aldom

I get Tesco’s delivery most weeks, no problems there.

They reduce the price of all three items - you need to check carefully. Their receipts can be very complicated, especially if you use your vouchers

My experience was not with Tesco.

I always accept a receipt. Sainsbury’s receipts are worth checking.
For me the worst offenders are Booths. I have had a number of £5 vouchers in apology for the errors.
Almost makes it worth being overcharged.

I always ask for a receipt in every supermarket. I've been double charged in Tesco, Lidl and Aldi in just the past 2 weeks.
Always ask for a receipt and check it before leaving the store.
Lidl are notorious for offering special prices but charging more .Supermarkets must make a fortune from people who decline the offer of a receipt at the checkout.