Hi, I hope you don't mind me asking but as I am in a similar situation and hope you may shed light.

The CGT on my main residence (sold feb 2014) in the Uk has a 100% exemption, so my £150k gain is tax free in the uk. I pay zero tax on the gain.

I move to Spain March 2014 and become tax resident for 2014.

My understanding is that due to the JTA between the Uk and Spain, if I am tax resident in Spain then my worldly income is taxable for that year. However CGT paid in the Uk can be offset against any CGT payable in Spain on my worldly income.
As I have paid zero CGT in the Uk on my £150k profit, I have zero to offset against Spanish taxes, so wouldn't the Hacienda want their bit?

I hope you can help me, sorry for potentially going over old ground.