Tesco Terry’s Chocolate Orange glitch made product just 29p each.

A computer error at the Tesco’s tills enabled surprised customers to pick up Terry’s Chocolate Orange for just 29p each – a tenth of their value.

Shoppers, who have taken advantage of the glitch at Tesco, filled their trolleys with boxes of Terry’s Chocolate Orange – advertised on TV by comedian Dawn French – and cleared entire stocks.

One shopper bought 192 packs of Terry’s Chocolate Orange, which normally has a retail price of £2.75, for just £57 – saving a staggering £471.

The rush started because two independent Tesco discounts were applied at the same time rather than consecutively:

1. Buy-one-get-one-free (BOGOF) offer is equal to £1.375 pounds per orange, half the £2.75 retail price.

2. £3.25 for every three you purchase (three for £5 when that many would normally cost £8.25).

So, if you buy six Terry’s Chocolate Orange, it would cost £16.50, less £6.50 (the three for £5 discount) and also less £8.25 for the BOGOF deal.

The total cost is therefore £1.75 for six packs of Terry’s Chocolate Orange – or just over 29p each.

The discount error is believed to have affected all main UK Tesco “Extra” supermarkets as well as their Metro stores – around 1,250 in all – but not the smaller Express outlets.

A spokesman for Tesco would not say how many Terry’s Chocolate Orange products were sold or how much it had cost the company.

Within hours, a Facebook page called “Terrys Chocolate orange glitch, I was there” has been created and flooded with people posting photos of their chocolate hordes as well as their receipts.

In the same time, the glitch had been posted on a money-saving website and 57 pages of comments had been posted from excited shoppers.

It was reported that people visited five different stores after clearing each shops’ shelves to make the most of the deal.

They were able to combine a three-for-£5 deal on another Terry’s Chocolate Orange with BOGOF offer.

However, the tills applied a further discount only when Terry’s Chocolate Orange was bought in multiples of six.

That meant Terry’s Chocolate Orange, which usually sells for £2.75, was being sold for 10% of the original price.

The Terry’s Chocolate Orange’s deal was first posted on money saving website www.hotukdeals.com at about noon on Tuesday.

After few minutes, the shoppers posted photos of their receipts – the first showed £8.95 being spent just on Terry’s Chocolate Orange, with £73.15 being saved.

According to a spokeswoman for Tesco, the error only lasted only “a couple of hours”.

She added: “We deal with 35,000-40,000 products, so sometimes these things happen. We have made lots of people very happy.”

“We are putting steps in place to make sure that it does not happen again.”

Kraft Foods, the producer of Terry’s Chocolate Oranges, were unavailable for comment.