Zoologists have revealed they have taught chimpanzees how to complete a self assessment form and calculate their own tax liabilities.

The chimps were among a group that had already mastered sign language and had been moved on to a test for numeracy skills among primates. The chimps, a group of 6, scored a remarkable 80 per cent success rate at calculating their own tax liabilities, substantially higher than the success rate reported for UK filers by tax officials.

The hit rate only fell when the chimps were asked to include income earned as interest in their calculations. Even then it was a remarkable 70 per cent.

Scientists began the exercise by teaching the chimps to part with a certain proportion of their daily banana allocation as a ‘lunch levy’.

The conclusions are set to revolutionise thinking about primate behaviour and inform the way tax experts construct self assessment forms and the self assessmentwebsite.

A spokesman said: ‘We think it might be easier for tax payers if we ask them to calculate how many bananas they owe us. Our thinking in this area is now entirely bananas.’

Confusion remained over non-doms and whether they would have to pay bananas from their overseas ‘bunch’. Owners of plantations could be particularly badly hit.

One non-dom told Accountancy Age he was feeling bruised and battered by the whole issue.