Q: My boyfriend and I recently purchased a home together. Although we each contributed 50 percent of the down payment, I pay 70 percent of the monthly payments and he pays only 30 percent because I earn a lot more than he does. When we complete our respective tax returns, will we have to divide the interest write-offs 50/50, or should we split them 70/30?

A: You personally pay 70 percent of the monthly mortgage-interest charges, so the Internal Revenue Service says you’re entitled to claim 70 percent of those payments, and your boyfriend should take 30 percent. For tax purposes, the fact that you each made half of the initial down payment won’t matter until the property is sold.

For unmarried couples who file their tax returns individually, the record-keeping burden is even heavier than it is for married people who file jointly.

For example, you and your boyfriend will need to keep separate sets of records to show how much each of you pay for the property annually, in case one of your returns is audited. The records also may be useful in divvying up profits and tax breaks when you eventually sell.

You and he also should have some sort of partnership contract or similar agreement that clearly spells out your individual financial commitments – not just how monthly loan payments will be split, but also how the annual property taxes, future repair or remodeling bills, resale profits and other items will be divided.

Each of you also should have a written will or inexpensive living trust, especially if either of you wants to leave your interest in the home to a relative.

Q: Is it true that some credit-card companies are now letting home buyers put their down payments on their credit cards?

A: Yes. Credit-card giant American Express recently announced that it would allow some of its customers to put their down-payment on their cards, and other companies are considering similar plans.

For now, AmEx’s novel program is limited to cardholders who want to charge their down payment to buy a condo in an upscale project in midtown Manhattan. But the company hints that one day the program might be offered across many other parts of the nation.

Personally, I’m not wild about the idea of using credit cards to buy a house: If you’re unable to save up enough money for a minimal down payment to get a conventional mortgage, you probably shouldn’t be buying a home to begin with, and might not be able to keep up with the monthly payments on both your credit cards and home loan if the deal is approved.