Question is, what do we need to do as far as the IRS is concerned? I
mean we'll get the money from them and pay it back less than two
You're probably worried about the gift tax. Since you're a couple, the maximum exclusion amount is calculated like this:
MAEA = MAEAp * Pr [ * Pg], where:
MAEA is the maximum exclusion amount per year in your situation;
MAEAp is the maximum annual exclusion per person receiving from any single gifter.
For 2014 MAEAp is $14000.
Pr is the amount of persons receiving the gift (2 in your case: you and your spouse).
Pg is the amount of persons giving the gift (2 in your case, your mother and father).
The reason the
Pg multiplier stands separate is that gift splitting does require form 709 filed even if no tax is due, unless they actually write separate checks for their respective portions.
So the math shows that you and your wife can get at least $28K from anyone without the need of gift tax to be paid or gift tax return to be filed. You can get up to $56K from your parents, but the gift splitting may need to be documented on form 709.
Since you're in fact talking about a loan you're going to repay, you'll need to document it (with a note and everything), and document the repayment. If interest is being paid - your parents must declare it on their tax return for the year, obviously. In this case, if the loan is properly documented, repaid and the interest is declared, the IRS won't even bother claiming it was a gift. Even if there's no real interest, it shouldn't be an issue (the IRS might assign some "deemed" interest at their rates that would be considered a gift, but assuming no other gift transactions between you exist for the year the amount would be miniscule and way below the $14K exclusion level).
Of course, as with any tax concern, you get here what you paid for. For a proper advice talk to a tax adviser (EA/CPA) licensed in your State.