Hi.So long as you sell (the date of sale is in most circumstances the date you exchange contracts) the house by 5 April 2015 you won't have to pay Capital Gains Tax in the UK as you are a long term non-UK resident. After 5 April 2015, CGT will be levied on non-UK resident owners of UK residential property which is sold but only on any increase in value from that date. So, in effect, the 5 April 2015 value of the property will become its cost for CGT purposes.You will always have a UK national insurance number. Assuming that you do not currently complete UK tax returns, you will not need to report the sale of the UK property to HMRC in the UK. If you were letting it which would compel you to complete an annual UK tax return except in certain circumstances, you would naturally report the disposal as part of your tax return for the tax year in which it was sold. If HMRC write to you and ask questions about the sale, you will have no problems in answering them as you are non-UK resident. From the HMRC point of view, it's just a matter of routine.I hope this helps but let me know if you have any further questions.