Is my company an SME?

This simple question is actually not so simple. The criteria used for R&D tax relief are the same as for Transfer Pricing and not the normal UK  Corporate Tax definition. It follows the EU definition described here.

There is a useful calculator tool developed as a collaboration between the European Commission, the Walloon Union of Enterprises, Belgium and the agency for administrative simplification in Wallonia, Belgium. Note that this is not provided by us and no responsibility is taken for the result of it.

Even if you are not an SME, there is a new category of mid-size companies who have between 250 and 500 employees that applies from August 2008. Details can be found here