There are three basic requirements for a UK patent. The patent must be:
2) involve an inventive step and
3) be capable of industrial application.
Problems will arise if your invention comprises a computer program or method for doing business. Where it is solely in relation to it computer programs or business methods it will not be regarded as an invention. However patent protection can be obtained for inventions implemented by computer programs. The question is whether the invention makes a technical contribution to what is already known in that field. A patent is unobtainable if the only inventive step relates to matter which is excluded from patent protection, such as a computer program.
The UK Intellectual Property Office (IPO) takes a negative approach to software and business method patents when compared to the European Patent Office (EPO) and the USPTO.
The test to decide whether a software or business method invention is capable of being patented (Aerotel Ltd v Telco Holdings Ltd (and others) and MacrossanÃs Application  EWCA Civ 1371).
To adhere to the 4 stage test you need to:
1) construe the claim properly
2) identify what the actual contribution is
3) determine if the patent falls within an excluded subject matter and
4) check whether the contribution is technical in nature.
The Court of Appeal in Aerotel found that a telephone system did fall within the normal 4 stage test whereas as in Macrossan it did not. The latter concerned a system for preparing documents for incorporating a company. It was not considered having any technical affect beyond running a computer program.