More than one form ____ to be completed.
I was thinking over the sentence : Less than two forms need or needs ?
Well, it has to be two because it says 'MORE THEN ONE.' It has to be 'needs' and I'm not bothering to explain why.
it could be 'more than one form need be completed' if 'to' is omitted
More than one form needs to be completed. More forms than this one need to be completed.
"Completion" is what is needed, not "forms", The plurality of "form" is irrelevent here. People always seems to forget what they are talking about. Something NEEDS to be completed - it doesn't matter how many forms there are.