Banks legally can charge a higher rate to a borrower with a low credit score, but it’s a trickier proposition for small-time landlords who want to base their rent on the same factor.

Q: I own a small rental property, and have been running advertisements to rent one of its vacant units for $850 a month. Several people with great credit scores have applied. But if I decide to rent it to someone with a below-average credit score, would it be OK to demand an extra $100 per month for the rent because their credit history isn’t good?

A: Federal law clearly permits landlords to consider an applicant’s credit score when making a rental decision, but rejecting an applicant with a good credit rating and instead renting to someone with a lesser score to make an extra $100 per month would be a bad idea.

First, the person with the good credit score is more likely to pay his or her rent promptly. I’d rather lease to a tenant whose score suggests that the bill will be paid on time, instead of renting the place for an extra $100 per month to someone who may not be as reliable – and perhaps later cost hundreds or thousands of dollars to evict.

Offering the unit at one price but then charging a higher fee to someone else because that person has a lousy credit rating could put you in jeopardy of a discrimination lawsuit – or maybe even two. To illustrate, let’s say that a single, black man with an outstanding score wants to rent the unit for your advertised price of $850 a month. You decline his application, and instead select a white mother of three children (despite her bad credit score) because you want her family to have a good place to live and figure that the $100 per month more that she’s willing to pay will offset any extra wear and tear that her kids might cause.

The mother could sue you after she moves in, because federal anti-discrimination laws generally prohibit landlords from charging more to someone who has children than someone who doesn’t.

Meantime, the black man whose application you rejected also would have grounds for a lawsuit: After all, his credit score was better than the white woman’s, and he was willing to pay your advertised price of $850 per month.

Considering such facts, it probably wouldn’t be difficult for the man to convince a judge that you had violated the fair-housing law that forbids landlords from discriminating against prospective tenants based on their race or ethnicity.

In short, select the rental applicant who has the best combination of a solid credit score and a steady income that suggests that the applicant will be able to pay his or her rent in the future. Doing otherwise, even if it might pay you more, simply wouldn’t be worth the risk.