Potential tenants asking for lower rent

[Dan Marl]

I never had this before but two potential tenants is asking for lower rent.  They saw the house, but I haven't ran credit/background/income check on them.

How do you guys deal with this?  Should I tell them I need to run the credit/background first before I can reconsider?  I am willing to lower rent if they have good credit/background/income.  One asked for lower rent with an 18-month lease.  

[Joe Villeneuve]

Then they're not potential tenants, unless they are correct in what the rent should be, and your rent is too high.  When you have two interested tenants, and they both want lower rent, they may be correct. 
Are they just asking for a lower rent in general, or do they have a specific number?  If both have the same specific number, once again, they may be right. What are you basing your rent on?  Why do they want to lower the rent?