In January the High Court demanded the re-examination of six companies' patent applications, saying that the UK-IPO was wrong to reject them on the grounds of their being software.
The UK-IPO, which told OUT-LAW.COM at the time that it was considering an appeal, has accepted the ruling and changed its advice to companies on the question of software patents.
"This ruling is a narrow one which places a greater emphasis on the substance of what has been invented than the words used in the claim," said a statement from the UK-IPO. "It does not have the effect of making computer programs generally patentable in the UK but it does allow innovators to enforce all aspects of their patentable inventions directly."
The question of what can and cannot be patented in the realm of software is a complex one which has been the subject of a number of rulings in recent years. The legislation provides that it is not possible to patent a computer program 'as such', meaning something which is only a computer program is excluded subject matter.
UK patent law comes from the European Patent Convention (EPC), but the UK-IPO has traditionally differed from the European Patent Office (EPO) in how it interprets the law, and is less likely to award patents to software inventors.
The legal tests for whether software should be awarded a patent or not were laid down when a case involving applications by Aerotel and Macrossan reached the Court of Appeal in 2006.
In January's High Court case Mr Justice Kitchin found that there were some types of patent applications that should have been allowable but which were rejected by the UK-IPO. It ruled in a case brought by six failed software-related patent applicants that their cases were unfairly rejected by the UK-IPO.
That ruling criticised the UK-IPO's approach in interpreting the Aerotel/Macrossan findings too narrowly, unfairly excluding all software patents.
"The question I must now consider is whether the decision prohibits the patenting of all computer programs and, in particular, those which under the old approach would have been considered to make a conventional computer operate in a new way so as to deliver a relevant technical contribution," wrote Mr Justice Kitchin in his High Court ruling.
"UKIPO has apparently concluded that it does and so has reverted to its previous practice of rejecting all computer program claims…I do not detect anything in the reasoning of the Court of Appeal which suggests that all computer programs are necessarily excluded," he wrote.
The Aerotel/Macrossan case produced a four step test which must be followed to determine whether something can be awarded a patent or not. That test asks that patent examiners: "i) properly construe the claim; ii) identify the actual contribution; iii) ask whether it falls solely within the excluded subject matter; iv) check whether the contribution is actually technical in nature".
The High Court backed that test, but took issue with the way the UK-IPO had applied it. It also agreed with the patent applicants when they said that the UK's interpretation should not differ too greatly from the EPO's.
"It is highly undesirable that provisions of the EPC are construed differently in the EPO from the way they are construed in the national courts of a Contracting state," Mr Justice Kitchin said. "The new approach can be interpreted to produce a result consistent with that obtained by applying the reasoning of the Boards of Appeal."