If you are not resident in the UK then HMRC will continue to tax you on any UK pensions and earnings from employment where duties are carried out in the UK. Investment income arising in the UK is also liable to UK tax and this includes income from property letting. This is of course subject to any Double Tax Treaties between the UK and your country of residence.

Other than the income tax implications of UK source income, expatriates can also remain liable to capital gains tax in the UK where they are regarded as 'temporarily non resident' for this purpose. They are also liable to capital gains tax on any UK property disposals. 

There is a common misconception that your 'home' is always exempt from UK capital gains tax however, this is not always the case. Basically, if you have been absent from a property for any length of time, these periods are not exempt from tax. There are however various reliefs and exemptions available and you should seek professional advice if your situation is not straightforward. UK property disposals now need to be reported to HMRC under the NRCGT reporting requirements as well as under Self Assessment. Non residents must report all sales or disposals of UK property within 30 days of the completion date, even if they have no tax to pay or have made a loss.

HMRC has powers to 'enquire' into an individual's Return form as well as withdraw approval to the Non Resident Landlord's Scheme if you fail to supply information requested from you. Under the Offshore Disclosure Requirements HMRC has also obtained Orders requiring a number of offshore banks and financial institutions to disclose details of customers who hold accounts outside the UK. Double Tax Treaties also include Articles to exchange information between various countries.

This is not necessarily the case as should you die intestate, i.e., without writing a Will, your estate will be subject to the rules of intestacy and your assets will be divided accordingly. This situation is even more complicated should you die intestate overseas, particularly in countries where Sharia Law applies. Professional advice is essential on this matter.