For insurance investments bonds there is a special rule that allows us to encash up to 5% pa cumulatively of the original investment without any immediate liability to tax as a UK Resident. If you have made past withdrawals (the previous question) did you exceed the 5% rule at the time? E.g. Original Investment £10,000. 5% pa = £500pa. Had the bond for 5 years, means cumulatively you could withdraw up to 25% of the original value (5yrs X 5% = £2,500) without a top slicing/tax calculation nor incurring an immediate liability to tax. The theory being over a 20 yr period (20 x 5%) = 100% of original investment cashed in and what remains is potentially taxable growth. ONLY INCLUDE AMOUNTS THAT EXCEEDED THE 5% at the time - at the time of past withdrawals you may have received a CHARGEABLE EVENTS CERTIFICATE from the investment bond company if this were the case.