A co-borrower shares the loan and usually the ownership of the home, and their income, debts and credit are all counted. On mortgages, a “co-signer” usually means a non-occupant co-borrower: someone, often a parent, who signs the loan to help you qualify but doesn’t live there. Either way, everyone who signs is fully responsible for the debt, and it appears on their credit.
Occupant vs. non-occupant co-borrowers
| Occupant co-borrower | Non-occupant co-borrower | |
|---|---|---|
| Lives in the home | Yes | No |
| Typical example | Spouse, partner, friend buying together | Parent helping a child qualify |
| On the title | Usually | Often, depending on program and choice |
| Program rules | Standard | Allowed for conventional and FHA, with conditions |
How a co-borrower changes your approval
- Income is combined, which can raise what you qualify for.
- Debts are combined too, including their own mortgage.
- Credit: lenders often use the lowest middle score among borrowers for pricing, so a co-borrower with weaker credit can raise your rate.
What it means for the co-borrower
- They’re legally responsible for the full payment if you can’t pay.
- The loan appears on their credit and counts in their debt ratios for future loans.
- Late payments hurt their credit as well as yours.
- Getting off the loan later usually requires a refinance; see removing someone from a mortgage.
Alternatives
A gift for a larger down payment can sometimes do more than a co-borrower without tying them to the loan; see using gift money. Down payment assistance and a less expensive home are other options; see the affordability calculator.
If you’re buying with someone you’re not married to, consider a written agreement about ownership shares, payments and what happens if one of you wants to sell.
Common questions
Can my parents co-sign my mortgage?
Yes. Conventional and FHA loans allow non-occupant co-borrowers, often family members, with conditions.
Whose credit score is used with a co-borrower?
Lenders often price the loan on the lowest middle score among the borrowers.
How do I remove a co-borrower later?
Usually by refinancing into your own name once you qualify alone.
Updated October 2026. Educational content. OfferBacked is not currently a lender and doesn’t issue pre-approvals or loans.