31 and 43: The Two Numbers That Almost Killed Donna's FHA Loan
Two Numbers, One Ballgame
31 and 43. Donna, a nurse near St. George, SC, had a credit score sitting in the high 500s and was applying for an FHA loan on a three-bedroom house. She had no idea those two numbers were about to decide her entire approval until her loan officer sat her down and explained what they meant.
A situation like Donna's comes up often: a borrower with elevated debt ratios or a credit score under 580 assumes one tight number is an automatic denial. It isn't always. But it does matter enormously which underwriting path the file takes.
Manual Underwriting vs TOTAL AUS
FHA loans get evaluated one of two ways: manually by an underwriter, or automatically through TOTAL Scorecard. These two paths produce very different debt-to-income outcomes, and most borrowers never hear the distinction explained until they're already deep into an application.
Here is the guideline, word for word: "For manually underwritten Mortgages, maximum qualifying ratios depend on credit score and compensating factors: MDCS 500-579 or No Score: 31/43, no exceptions; MDCS 580+: 31/43 with no compensating factors, 37/47 with one compensating factor, or 40/50 with two compensating factors and no discretionary debt. For TOTAL AUS scored Mortgages, the DTI is evaluated as part of the overall risk assessment without a fixed cap. FHA does not use residual income as a primary measure like VA."
For Donna, with a score in the high 500s, a manual underwrite meant a hard ceiling of 31/43, with no exceptions available. That is a firm number, and it does not bend regardless of how strong the rest of the file looks.
Why This Matters Before You Apply
The reason this distinction matters so much is that it changes what's negotiable. If a file is manually underwritten and the credit score is 580 or higher, compensating factors can open the door to 37/47 or even 40/50 ratios, provided there's no discretionary debt. Under 580, that flexibility disappears entirely. TOTAL AUS files are different still: debt-to-income gets weighed as part of an overall risk picture, without a fixed ceiling, because the automated system is looking at the whole file, not just one ratio in isolation.
That means two borrowers with identical ratios can get completely different outcomes depending on which path their file takes. Knowing the path before ratios become the sticking point is what allows compensating factors to be built into a submission proactively, rather than scrambled together after a denial.
The One Question to Ask
If you are applying for an FHA loan with a credit score under 580, or your debt ratios feel tight, there is one question worth asking your loan officer, word for word: is my file manual or TOTAL, and if it's manual, which compensating factors do I already qualify for under Section II.A.5.c.viii? That question alone tells you which rule applies to your file and what room, if any, exists to work with.
FHA does not use residual income as a primary measure the way VA loans do, which is exactly why understanding your ratio ceiling matters so much on this specific loan program. The ratios are the measuring stick, and knowing which version of that measuring stick applies to you changes how you prepare.
If you're working through an FHA application and want to know exactly where your file stands, reach out. I'm Jason Sharon, licensed mortgage broker at Home Loans Inc, and I find the path.
Home Loans Inc - Jason Sharon, Mortgage Broker. Company NMLS #1728740, Jason Sharon NMLS #1281448. Equal Housing Opportunity.
Learn more about this loan program: 31 and 43