Fashion website ASOS is fighting attempts by a rival retailer to make it change its name in Germany.
Anson's, which does not sell online, believes their names are too similar and has mounted a legal challenge to prevent the use of ASOS for clothing sales in Germany.
A court hearing will be held on May 3 in Hamburg to determine whether there is a danger of customer confusion, which could result in ASOS being forced to operate under a different name in Germany.
ASOS has rejected the claims and hit out at Anson's for being "opportunistic".
A spokesman for ASOS said: "There is zero evidence of confusion between Anson's and ASOS. The claims are being fought vigorously and ASOS remains confident of its position."
The challenge comes shortly after the group posted strong growth in its international business, which now accounts for 52% of all turnover.
Anson's, which was established in 1989 and has 21 stores in 17 German cities, said it had brought the case due to the oral and written similarities around the two brand names.
Anson's has already successfully applied for two preliminary injunctions against ASOS.
ASOS may have to completely rebrand in Germany - one of its five strategic growth markets - if Anson's is successful.
The company was founded in 2000, and attracts more than 11 million unique visitors a month.