norman et al,
sorry to butt in here as a CX big brother but I think it would be handy to know some tax stuff.
First thing...hkg 'provisional' tax. In oz, we call our tax PAYE...pay as you earn. I am sure the UK has the same thing but with a different name. So lets say you joined a company, in the UK, on April 1st and you were going to earn X pounds per year. If your tax owing for the entire Apr 1st to Mar 31st tax was Y, how much of Y would you have paid by Jan 1st....about 75%. Well despite scaremongering, that is exactly how it works it hkg. You end up paying tax on money you have already earnt. So for people that complain of huge tax bills after a year or two, its because they haven't being paying any tax at all for those 2 years.
In summary, you wont have to pay tax on any money you haven't already physcially got in your pocket already!
Second thing...you almost never get double taxed. I can only speak from antipodean experience but since our law(tax law) is completely based on UK law, I am almost certain it applies.
Lets keep it simple...hkg and UK tax people may think you are a dual resident. As such you have to pay tax in both countries. Almost all countries have an agreement that allows the main country to tax first then the secondary country. So, in australian english, if hkg decides you live there first, you pay your 16% tax. After that, mother england decides you should pay Z% of your gross salary to mr brown(is he still there?). BUT, you get to reduce that payment by what you have already paid to HKG. So you are no worse off than if you were ONLY a resident in UK. If, for argument sake, you were in HKG less than 60 days, you wouldnt have to pay hkg tax, but you would still have to pay Z% of your gross salary to UK IRD. So you pay the HKIRD 0, since less than 60days, then pay UK taxman Z% of gross salary less hkg paid tax!!!!!!
So at the end of the day you pay the tax of the highest country you are resident of.
To summarise.
In HKG, by the time you pay tax you will already have been paid the income...ie it is the same as a time lag PAYE
The total tax you pay over two countries will almost always be less than or equal to tax payable in the highest taxing country.
clear as mud?