Is trademark registration necessary even when the mark has been in use for many years?

In countries which have a legal system based on common law, "prior use" is generally sufficient for claiming rights over a given trademark in case of dispute. In civil law countries, however, this is usually not the case. Only trademark registration will provide legal certainty on exclusive rights to the use of the trademark regardless of how many years an enterprise has been using the name. Even in the first case, it is highly advisable to register a trademark, as registration will reinforce the position of the right holder in case of litigation.