Every year during Black Friday there are both genuine and fake deals advertised as on sale, according to price comparison service PriceRunner who analyse thousands of sale prices every year.

Last year they found that every fifth discount in their analysis was actually a fake deal.

A fake deal is when retailers subtly increase the price of a product ahead of a sales season to then lower them in time for the sale, creating a fake or inflated impression of a sale.

Christine Gouldthorp, consumer expert at PriceRunner, said: “This incredible sneaky sales tactic is not illegal but highly inappropriate, tricking consumers into thinking they are getting a much better deal than they actually are. I urge consumers to be mindful during Black Friday and always compare prices before they buy.”

Scottish shoppers are starting to catch on to this fact, according to a survey carried out in October by YouGov of more than 2,000 people in the UK. When asked if they trust the deals they see advertised on Black Friday, a third of Scots said they never do.

When able to choose as many options as applicable, the most popular way Scots find out if a deal is genuine or not is by comparing prices directly on different websites (62%), where the fourth most popular option is to use a comparison service (19%) instead.

With the big day coming up this Friday, a third of Scots said in the survey that they plan to buy discounted products during the Black Friday sale, with more than one in four planning to spend up to £500 on bargains.

To find out the possible number of fake deals this year, PriceRunner has been keeping track of prices on more than 20,000 products since the end of August from the UK’s 50 most popular retailers.

Prices have already started to increase ahead of Black Friday, as 13% of all tracked products have increased in price by on average 19% This indicates the possibility of a large number of fake deals during Black Friday this year as well.

A further third (29%) of Scots are worried that the products they may want to buy during Black Friday might not be for sale due to the ongoing HGV crisis.

According to data from PriceRunner, some of the products that are largely out of stock and might be hard to get your hands on right now are toys (12%), laptops (38%, watches (30%), tablets (30%), game consoles (28%), TV’s (26%) and golfing products (25%).