Paying Pension From Foreign Country

Hi, I'm a Hungarian national, with residency status in the UK. I've recently started receiving my Hungarian pension, and I've been told I need to pay taxes on that income. I am currently not retirement age in the UK and I'm a full time employee. I've tried to go through the online forms, but I've found it all a bit confusing. Is there someplace I can contact someone, or agencies that can help me with providing my self asssessment, or if I even need a self assessment or I can just provide some documentation from the country I'm getting my pension from. Many Thanks.

Hi Ferenc Grill, 
You need to declare this income in a tax return so if not already registered for Self Assessment you will now need to register.
Further guidance is available here:
Tax on foreign income
Once you have read the guidance and are need further help, you can telephone 0300 200 3300 for advice.
Thank you.