Where a UK residential property is disposed at a gain and a 30-day CGT return is required, an estimate of the tax payable on the gain is also required in the same timeframe. In the last month, it has transpired that where the payment of the estimate is too high, HMRC's computer system currently does not automatically offset the overpayment against the self-assessment bill. The only way to recover the overpayment is to either resubmit the 30-day CGT return (where this is possible), or contact HMRC to request a manual offset. HMRC has now responded to a number of queries covering a range of scenarios from several professional bodies by producing a helpsheet. The most noteworthy of these are as follows:

• the 30-day return cannot be amended once a self-assessment tax return has been filed;
• where the initial estimate was too low, no interest will be charged unless the estimate is found to be “unreasonable”;
• where a 30-day return is amended and there is an overpayment, there is a section on the return to request a repayment. However, unless the most recent payment on the system was made using a card it will not be automatically refunded, and HMRC must be contacted to request a refund - there is no section to include bank details yet.