There are typically two specific types: a Permanent Buy down, and a Temporary Buy down.a) In a Permanent Buy down, a sufficient amount of interest is prepaid to lower the rate permanently. b) In a Temporary Buydown, only a sufficient interest is paid to lower the payment for the first three years. 1) The reason to temporarily “buydown” a loan is to lower the current payments, thereby more easily qualifying for the loan.

US Dept. of Justice on Realtor Rebates        https://www.justice.gov/atr/rebates-make-buying-home-less-expensive         https://www.justice.gov/atr/competition-and-real-estate-state-31                                                                  FREC (Florida Real Estate Commission) Rule 61J2-10.028 paragraph (2)The sharing of brokerage compensation by a licensee with a party to the real estate transaction (i.e. the buyer or seller) with full disclosure to all interested parties is not considered a violation.Facts: Seller Concessions to pay for Buyer's closing costs and prepaids are NOT the same as REALTOR REBATE. 

Encourage tenants to pay their rent and utility bills automatically through "bill pay" with their bank or by electronic funds transfer or debit card via a third party service that deposits the funds directly into your account.Bottom line though.... if the tenant can't (or won't) pay, they can't stay.

Going through a downturn with low or no debit very well may be the catalyst to the next 20 units so rather then chasing deals I want to bullet proof my portfolio.

We're pretty solid financially and have zero debit other than our mortgage and regular monthly bills.

They do this through a combination of a) The stated rate of interest, b) The points (pre-paid interest) they charge and c) The fees they charge for things like: loan releases, draws and extensions. 

You'll have to pay points and fees at closing, along with other closing costs (escrow fees, title insurance, prepaid hazard insurance, prepaid interest, prorated taxes, etc).  

Either with a linked debit card or checks.Are the payments interest only or interest and principal?

So if your tenant does not want to sign up for the auto rent debit offered via Apartments.com (or any other tool), then you'll have to stick with depositing paper checks. 

There are some great options out there which can help you by breaking out those fees, and also offers automated maintenance tracking, and fast rent collection (via ACH or debit/credit card).