Renting the Spare Room or the Garage Apartment: When Boarder Income Counts

A cousin doing his master's at UT Dallas has been paying you $800 a month for the front bedroom for the last year and a half. He pays by Zelle, on the third, every month. You are buying a house and your loan officer says that money does not exist.

She is mostly right. Fannie Mae's Selling Guide B3-3.4-04 says boarder income is generally not acceptable as qualifying income. That is the default, and most of the time it is the end of the conversation.

But there are two written exceptions, and one of them was designed for exactly this household.

Exception one: a live-in personal assistant

A borrower with disabilities who receives rental payments from a live-in personal assistant may use that income, capped at 30% of total gross qualifying income. The personal assistant is usually paid from a public agency or from a disability benefit, and the payment to the borrower is rent. Narrow, real, and worth knowing exists.

Exception two: HomeReady, and this is the one that matters

Under B5-6-02, a HomeReady loan permits boarder income on a one-unit property. The conditions are specific and every one of them is checked:

• Boarder income may not exceed 30% of total gross qualifying income.

• The boarder must have lived with the borrower for the last 12 months.

• The boarder may not be on the mortgage note and may not have any ownership interest in the property.

• Documentation is 12 months of documented payments, or at least 9 of the most recent 12 months of payments, averaged over 12.

• Shared residency must be documented.

That nine-of-twelve provision is the quiet mercy in the rule. Your cousin went home to Hyderabad for six weeks last summer and paid nothing in July or August. Ten payments in twelve months still works — averaged over twelve, not over ten.

Proving shared residency

The Selling Guide expects evidence that the boarder actually lived with you. In practice the file gets built from documents that put both names at the same address: a driver's license, utility or phone bills, bank statements, W-2s. Two or three independent sources at the same address for the same period is what gets an underwriter comfortable.

Documented payments means traceable payments. Zelle, Venmo, ACH, a check deposited to your account. Cash on the kitchen counter is not documentation, and no amount of explaining will make it one.

The 30% cap is not what most people calculate

This is where the arithmetic surprises people, so work it slowly.

The cap is 30% of total gross qualifying income — total including the boarder income itself, not 30% of your salary.

Take Sneha, a composite of files we see in Irving. Her base salary is $67,200 a year, or $5,600 a month. Her cousin pays $800 a month.

If she counts the full $800, total qualifying income is $6,400, and the boarder share is $800 / $6,400 = 12.5%. Well inside the cap. All $800 counts.

Now push it. What is the most boarder income she could ever use on a $5,600 salary? Solve for B where B is 30% of ($5,600 + B): B = 0.30 × $5,600 / 0.70 = $2,400. At $2,400 of rent, total qualifying income is $8,000 and the boarder share is exactly 30%.

So the cap is more generous than it sounds — but the real constraint is almost never the percentage. It is the program.

HomeReady's accessory unit rule

HomeReady also allows rental income from an accessory unit on a one-unit principal residence. That covers the converted garage with its own entrance, the casita, the mother-in-law suite with a kitchenette — where the unit is legal and the appraiser treats the property as one unit with an accessory dwelling.

This is a different income type from boarder income, with different documentation. If your property has a real second unit rather than a rented bedroom, tell your loan officer that in the first conversation. The two get confused constantly and they do not follow the same rules.

The part that gates all of this

HomeReady carries an income limit: 80% of area median income. Everything above — the boarder income, the accessory unit income, the 3% down payment — is only available if your household income sits under that line.

A dual-income household in Frisco, Plano, Fremont or Johns Creek will clear 80% AMI without effort, and clearing it is disqualifying here. New AMI limits took effect June 13, 2026. We go through the limits and who actually fits in 3% Down and HomeReady in 2026.

Sneha at $67,200 in Irving is a real candidate. A couple at $215,000 combined in Frisco is not, no matter how long the cousin has been paying rent.

If you are over the income limit: buy units, not rooms

For the household that earns too much for HomeReady and still wants the rent to count, the answer is to stop renting a room and start owning a rental unit. A 2-4 unit property where you occupy one unit is a principal residence purchase, and the rent from the other units is actual rental income under the standard rules — not boarder income, not capped at 30%.

	Spare room, standard loan	Spare room, HomeReady	2-4 unit, you occupy one
Rent counts as income	No	Yes, up to 30% of total gross qualifying income	Yes, as rental income
Income limit	None	80% of AMI	None
Boarder must have lived with you 12 months	n/a	Yes	No
Minimum down payment	Program dependent	3%	Higher than a one-unit; program dependent
Borrower's own funds required	None on a 1-unit principal residence at any LTV	None	5% of the purchase price above 80% LTV
Documentation	n/a	12 months of payments, or 9 of 12 averaged over 12	Leases, Form 1007, or the B3-3.1-08 routes

That 5% own-funds rule on 2-4 units above 80% LTV is the one that catches families planning to fund the purchase with a gift from parents. On a one-unit principal residence, there is no minimum borrower contribution — every dollar may be gifted. Move to a duplex above 80% LTV and 5% of the price has to come from your own money. On a $700,000 duplex, that is $35,000 you cannot receive as a gift.

If you are also weighing whether the parents move in, Buying a House Big Enough for Your Parents covers the pooled gift rule that makes that work. If you are heading toward a portfolio rather than a house with tenants in it, read The 10-Property Limit and the Reserve Ladder before you buy the second one.

What renting a room actually costs you

Rent from a boarder is income, and income has tax consequences. Renting part of your home can change how you allocate mortgage interest and property taxes, and it can affect the treatment of the property when you sell it. Your homeowner's insurance policy may also treat a paying tenant differently from a guest, and some policies require notice.

Neither of those is a mortgage question. Take both to your CPA and your insurance agent before the first rent payment, not after.

What not to do

Do not start collecting rent from a cousin in March so you can use it in an application in June. The 12-month shared-residency requirement is a look-back at a life you already lived, not a plan you can start executing. Underwriters read the payment history and the shared-address documents together, and a pattern that begins right before a purchase reads exactly like what it is.

And do not describe a family member who is contributing to the household as a boarder if they are actually a co-borrower or a gift donor. Those are three different structures with three different rule sets, and picking the wrong label costs you the file.

Frequently Asked Questions

Q: Can I use rent from a roommate to qualify for a mortgage?
A: Generally no. B3-3.4-04 says boarder income is not acceptable. The main exception is HomeReady under B5-6-02, which allows boarder income up to 30% of total gross qualifying income on a one-unit property, if the boarder lived with you for the last 12 months and you can document the payments.

Q: How do I document boarder income?
A: Twelve months of documented payments, or at least 9 of the most recent 12 months averaged over 12. Payments must be traceable — bank deposits, Zelle, ACH, checks. You also need shared-residency proof putting both names at the same address, such as a driver's license, bills, bank statements or W-2s.

Q: Does income from a mother-in-law suite count?
A: If the property is a one-unit principal residence with a legal accessory dwelling unit, HomeReady allows accessory unit rental income. That is a different income type from boarder income, with its own documentation. Confirm with your loan officer how the appraiser classifies the unit before you count on it.

Q: What if my income is too high for HomeReady?
A: Then boarder income is not available to you on a standard conventional loan. The alternative is buying a 2-4 unit property and occupying one unit, where actual rental income counts under standard rules. Note the 5% own-funds contribution requirement on 2-4 units above 80% LTV.

Q: Can my boarder be on the title?
A: No. Under B5-6-02 the boarder may not be on the mortgage and may not have any ownership interest in the property. If the person is going to be an owner, they are a co-borrower or a co-owner, not a boarder, and the file has to be built that way from the start.

Ready to get started? Masala Loans by Matador Lending specializes in exactly this. Call 713-366-4668 or get your no-haggle rate at masalaloans.com.

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