With self-checkout machines being a common feature in Aldi stores across the UK, customers will be all too familiar with using them.

However, many have now been left outraged after discovering a little-known rule for those hoping to buy in their weekly shop.

Some customers expressed anger at the inconvenience caused to themselves while others have said they are concerned about how little this rule has been publicised.

Aldi shoppers outraged after discovering little-known rule at self-checkouts

Hearts Standard: Aldi stores across the UK have self-checkout machines.Aldi stores across the UK have self-checkout machines. (Image: PA)

Taking to X, formally known as Twitter, one Aldi shopper asked the chain: "Since when did you have 20 items or less on your self-service checkouts?

They went on to complain about the lack of signage, telling the company: "There is no sign saying so. Be nice to know in advance which self-service checkout I can go to."

An Aldi customer service representative was quick to reply, telling the shopper: "All stores currently have a 20-item limit on self-checkouts.

"This change is designed to make it simpler and more efficient for you to shop with us. All customers can still use checkouts managed by our amazing colleagues!"

Hearts Standard: There is a 20 item limit at Aldi self-checkout machines across the UK.There is a 20 item limit at Aldi self-checkout machines across the UK. (Image: Getty)

While this rule has been in place for quite some time, others shared their bad experiences with it.

One user said that he was "stopped" by staff because he did not meet the requirements to use the machines.

He added: "Doubt I'll use this branch again, as waiting for usual till queue takes ages!"

Others have said that they are less than impressed by the self-checkouts with some saying they 'refuse to do the shop's job for them'.

When the rule was first announced, an Aldi spokesperson said: "This change will make shopping at Aldi even simpler and more efficient for our customers and has been designed to further improve their experience in-store.

"All customers can still use checkouts managed by our amazing colleagues."