Is it absolutely 0% or is it 0% with a $10/month administration fee? If the former, don’t pay it off early, just set up a standing order/direct debit and let it pay itself down. If the latter, you need to calculate the comparison rate (which will get higher the closer you get to zero balance), and work out what the break even is. Then carry on paying until you hit the point that the effective interest is greater than the interest on your savings account and at that point pay it off in full.