Loan repayment going towards mortgage

[BJ Butler]

In the last 3yrs, I have loaned a couple some money that has totaled approx $15,000. This includes cash and items charges to my credit card on their behalf. Yes, we have a contract and I keep the receipts. As we approach the repayment portion time, I was reminded I would probably have to pay taxes for anything over $10,000 that is given to me. They will be able to pay all this back with one check. With all the interest I will have accrued, my total balance will probably come to $20k. My question is this, instead of accepting cash then paying taxes on it (which is a lost on my end), am I able to have the couple just pay this large sum of money towards my mortgage? By doing this, it would allow me to refinance my home, take out a larger HELOC, & I remain within my legal rights as well as ethical. BP, your thoughts please.