Registering your trade mark is entirely voluntarily, but it is advisable.  This is because a registered trade mark gives the proprietor the exclusive right to use the trade mark in respect of the goods and / or services it is registered in relation to.  Trade marks are territorial, so depending on where you choose to register your mark, i.e. in the UK, the European Community, or the US, you will be protected in that territory.  Once your mark is registered, you are entitled to affix the ® (registered symbol) alongside of the mark, thus putting third parties on notice that your mark is registered.

Once your mark is registered, you will be able to ‘exploit’ your mark and licence or assign it to third parties for remuneration. 

Most importantly, a registered trade mark will give you the right to sue any third parties for trade mark infringement who use an identical or similar mark in connection with identical or similar goods and / or services without authorisation, where the use has caused or is likely to cause confusion.   In certain circumstances, the proprietor can even prevent use of an identical or similar mark on dissimilar goods and / or services.

In summary, a registered trade mark is a valuable commercial asset which gives the proprietor an exclusive statutory right to use the mark in the territory (and in relation to the goods and / or services) it is registered in relation to.