If there was no mention of a broker fee online where you found the home nor on the application you submitted, then it seems to me that the landlord should pay for the broker fee. That's a cost of owning and renting property. However, I don't know how good a deal the property is or how competitive a rental market you're in. If you have lots of other choices to rent, then you're in a strong negotiating position to refuse to pay the fee. If this is a rental you couldn't easily replace and they've got lots of other applicants, then you might consider a compromise -- offering to pay part of it just to get your foot in the door.