When I first started out renting property I made a few losses that I have been able to carry forward to offset against the profits I now make. Up until this years return I was able to enter the total amount for losses carried forward. This year, however, it appears that I am only able to enter an amount up to this year's profit figure. Figures for example purposes only (not real figures). Loss last year carried fwd £10k (box 43 from 2016-2017), profit this year £6k (box 3. I was expecting to be able to enter 10k in box 39 but am only able to enter up to £6k. Please advise how to account for the remaining £4k?