Is there a good or bad time to pay a lumpsum off your mortgage (putting other financial commitments aside as currently I have emergency funds, other savings/investments covered etc.). Currently on year 3 of a five year fixed rate at 3.35% (25yr term altogether) - likely to switch after year 5 when i get the cash back offer. Overpaying by 10% which is all that is allowed at present. Would it make a difference interest wise if I pay off the 10k lumpsum now versus in 2 years time, is one a better financial move to make than the other? Also, I heard about selecting to pay your sum at a specific time of the month - either before or after your interest is calculated - not sure which or if this is achievable to manage to get the timing right. The overall goal is to pay off the mortgage in a lot less years than I took out the original term for at 25yrs - hopefully 10-15 yrs.