I have on this check in form:
The problem with using one label for all three input boxes is that an non-sighted user is not going to know which of three boxes the focus is in because the same text will be read out in each case. There's a number of approaches possible. Maybe the safest is to have a label for each box, but hide those labels off to the left side of the viewport. Another possibility which ought to work, but I haven't tested would be this: