Fall Behind In/On

"He fell behind in/on his rent."

Which preposition (in, on) is more appropriate right after "behind"?

It's "in".

'with' would be better still.

Rover

NOT A TEACHER.

I don't see anything wrong with using "on." Perhaps this is a matter of American English versus British English.

A Scandal and a Debt
In the new year, however, he fell behind with his rent and wrote to his landlord Captain John Hamilton...

Maine Budget Matters » Gov. LePage’s Budget Proposal is Bad for Maine Families and Workers
Families and individuals often apply for GA when they are in crises like the loss of a job, something that would cause them to fall behind in paying their rent or paying for heat.

http://help.donorschoose.org/euf/ass...her_button.png

"On the rent" here. He fell behind on his mortgage.