Hi guys
Just to clarify the matters, each person gets $80,000 of their foreign source earned income exclusded from taxation if their tax home is outside of the US. If you make $90,000, and your wife makes $30,000, you will get an exclusion of $80,000 for you and $30,000 for your wife. Your additonal $10,000 income will be subject to fireign tax credit. Another words, you will be able to claim a credit for UK taxes that you pay on your US return thereby avoiding double taxation. You should be aware that once in a foreign country, your overall effective tax rate (once you have done your US taxes and UK taxes) is that of a country with the higher tax rate . In this case it is UK.
UK will tax you on your benefits as well as your salary and bonus. So, yes, they will tax the COLA, housing, car allowance , etc....although this may not be the case, if you are coming to the UK for a period of less than 2 years provided that you are sent to the UK by your US employer.
If you have any more questions, let me know...
Helen