Is this the world's most costly yellow circle?

Logo battles between brands can get ugly – and they also get hugely expensive. Germany's Lidl has won a high-profile case against Tesco, and the decision could cost Britain's biggest supermarket operator dearly.

At issue was Tesco's use of what might seem a very simple design involving a yellow circle on a blue background, but the colours and shape bear a notable resemblance to the Lidl logo (see our guide to how to design a logo for tips for your own work).

The German value supermarket chain Lidl took legal action against Tesco arguing that the colours and shape of the design the UK chain uses to promote discount prices offered by its Clubcard loyalty scheme took "unfair advantage" of the Lidle logo. In April, the High Court in London agreed. Now, in the latest development in the Tesco vs Lidl logo battle, the court has ruled that Lidl can be awarded an injunction to block Tesco from using the design.

Judge Joanna Smith said that “the only certain way to put an end to the loss that Lidl is incurring by reason of the continuing use of the signs is to grant a final injunction”. According to Reuters, the court was told that the decision could cost Tesco close to £8m because of the number of design pieces that will need to be changed across its stores and digital platforms. Ouch!

Tesco is appealing against the decision, arguing that it should be allowed to pay a small amount of damages instead. If its appeal fails, Tesco will have nine weeks to remove all of its yellow circle Clubcard logos. We can't say whether Tesco's use of the same colours and shape as Lidl's was intentional or not, but it just shows how brands need to tread carefully when using very similar logos to rivals (also see our roundup of the biggest brand battles in advertising).