Employment Foreign income

Hi, I have 2 sources of employment income, a uk and a foreign income from spain. I have PAYE for the uk income, however i need to submit a self assessment for the foreign income. Im doing this via a tax filer website Im not sure what deductions paid in spain can be claimed for tax relief under the DTA I have these questions: > In Employment SA102, for UK income 1) Pay from this employment before tax was taken off: Is this the GROSS salary before any kind of deductions including NI? 2) UK Tax taken off: Does this include NI or not? > In Employment SA102, for Foreign income 1) Pay from this employment before tax was taken off: Is this the GROSS salary before any kind of deduction like income tax and Social Security and medical Insurance? or can i discount those 2) UK Tax taken off: Should be 0? > Foreing SA106, for Foreign income 1) Amount of income on which tax is payable: Is this the same value as SA102 (1) ? 2) Foreign tax paid: Can include income tax, social security and private medical insurance? or some of those items are not allowed Ive read the DTA but its not really conclusive what can be claimed as relief. In spain the big deductions are Income tax, social security and medical insurance, and  I wish to understand what can be claimed in the uk. thanks a lot

Hi plane123456,
To declare foreign employment income, you need to declare it under the employment section (box 1, SA102 on a paper tax return).
This brings the foreign employment income in to the tax calculation.
Box 2 on SA102 is only for UK tax paid, so should be blank.
Tax should not be deducted from your Spanish employment (you may need to apply to HMRC for a certificate of residence, to claim any Spanish Income Tax back.
How to apply for a certificate of residence to claim tax relief abroad.
Where tax is payable in Spain, you would claim a Foreign Tax Credit in SA106 (foreign) page or the online equivalent.
Gross pay is before any deductions.
For Self Assessment the only tax permitted is Income Tax.
All others such as Social Security are not Income Taxes and are not covered by the tax treaties.
Self assessment does not collect Class1 National Insurance Contributions (NIC)
Any additional Class1 NI due, needs to be paid by you separately from Self Asssessment.
You will need to contact the the NIC helpline at 0300 200 3500 for further information.
National Insurance: general enquiries
Thank you.