You should take the allegation seriously, and it is best to seek professional advice as soon as possible.
A trade mark attorney can assess whether or not you are actually infringing and, if necessary, if there are any defences to infringement.
Then, depending upon the circumstances, an appropriate strategy can be developed for responding to the allegation of infringement. This could, for example, involve arguing that there is no infringement and/or that the trade mark is invalid, or making an offer to settle.
The appropriate way to address a particular allegation of patent infringement will depend upon the legal, factual and commercial situation. The majority of trade mark infringement disputes are settled out of court.
Wilson Gunn can advise on all aspects of intellectual property protection. Please get in touch to speak to a member of our team about trade mark protection.