But an IR spokeswoman indicated it wouldn’t be contacting taxpayers directly as it didn’t have an easy way to tell who paid tax under the FIF regime, let alone who among them would have had losses on the quick sale of shares. The proportion of investors who may have overestimated their taxable income this year as a result of the faulty calculator is expected to be small – especially given the vast majority of foreign shares rose in value in the year to April. The proportion who may have overpaid tax last year could be higher, given the big Covid-related plunge in share prices in the first quarter of 2020.