Workers in the City of London should take particular care with their tax return given the UK authorities’ more hard-line approach towards those with offshore bank accounts and rental income, say James Hender at tax advisors Smith and Williamson. City workers and others who have received bonuses or who hold shares in employer share schemes can face a particularly complex tax position which must be resolved before completing their annual self-assessment tax return. “People should also remember that HM Revenue & Customs has been tightening up on how it uses statistical information, notably regarding income derived from offshore bank accounts and rental property," said Mr Hender. He continued: “HMRC has decades of information relating to interest on UK bank accounts, but it has rarely been applied in the past. People often work from the previous year’s tax return when completing their form, but I would urge caution here. “People often assume they can sort out all their tax issues with HMRC via their on-line self-assessment forms. But this is frequently not the case. “Although the income tax on share incentives is usually dealt with through PAYE, the capital gains tax position on the disposal of shares can be extremely complicated. Not only can HMRC’s online filing website not cope with capital gains, detailed knowledge is often required before you can even start to calculate the figures. “One of the main difficulties for individuals is that many employers run several share schemes in parallel. Staff may build up their quota of shares in different schemes over the years, and sell some at intervals. “What’s more, people may change employer every few years which adds yet further complexities. Similarly, they may have rental property, other investments or be based offshore for some time. Taking all these factors together makes it very hard for an individual to sort out their own tax affairs.”