I worked in my local tax office for the summer, you dont need the landlords pps just name and address, its up to the tax office to find out if hes registered or not. but you can only claim tax back (paye) once i.e. if you sent in your p60 for 2008 this yr and got tax refunded then that is all the tax back you will get for that year. you cant claim tax back in rent relief, medical or education expenses on top of that. I made the mistake of thinking I could apply for rent relief and I already had recieved tax back for a few weeks of the year I had not been working and I was told that there is a maximum of tax back you can get and if you have already recieved tax back once you wont get it back on anything else in that year. you can claim for the last 4 yrs.