# Manual underwriting

> Manual underwriting is a loan review by a human underwriter using the program’s written rules, not an automated approval. When it’s used and its limits.

URL: https://mail.mortgage-math-us.com/glossary/manual-underwriting/  
Last reviewed: 2026-10-29 · By the MortgageMath US Editorial team

## Quick answer

**Manual underwriting** is a review of a mortgage application by a human underwriter applying the loan program’s written guidelines, rather than relying on an automated system’s approval. It’s used when the automated system refers the file or can’t evaluate it, for example a borrower with no credit score, and its limits are usually stricter.

## Key facts

| Fact | Value | Source | As of |
|---|---|---|---|
| Fannie Mae maximum DTI, manual | 36% | [Fannie Mae Selling Guide B3-6-02](https://selling-guide.fanniemae.com/sel/b3-6-02/debt-income-ratios) | Apr 2, 2025 |
| Fannie Mae, manual with strong credit and reserves | 45% | [Fannie Mae Selling Guide B3-6-02](https://selling-guide.fanniemae.com/sel/b3-6-02/debt-income-ratios) | Apr 2, 2025 |
| FHA housing ratio, manual | 31% | [HUD Mortgagee Letter 2026-11](https://www.hud.gov/sites/default/files/hudclips/documents/2026-11hsgml.pdf) | Oct 8, 2026 |
| FHA total DTI, manual | 43% | [HUD Mortgagee Letter 2026-11](https://www.hud.gov/sites/default/files/hudclips/documents/2026-11hsgml.pdf) | Oct 8, 2026 |

## Stricter limits

*Manual underwriting limits compared*

| | Fannie Mae | FHA |
|---|---|---|
| Total DTI | 36%, up to 45% with the required score and reserves | 43% without compensating factors |
| Housing ratio | No separate limit | 31% without compensating factors |
| Minimum credit score | 620 on fixed-rate loans | 500 |

By comparison, Fannie Mae’s [automated underwriting](https://mail.mortgage-math-us.com/glossary/automated-underwriting/) can approve a [DTI](https://mail.mortgage-math-us.com/glossary/debt-to-income-ratio/) up to 50%.

## Preparing a manual file

Compensating factors such as extra [reserves](https://mail.mortgage-math-us.com/glossary/reserves/), a new payment close to your current rent, or steady income the lender didn’t count can justify ratios above the baseline where the program allows. Expect the underwriter to read bank statements line by line and ask for written explanations of late payments, gaps in work or large deposits. With little traditional credit, the lender may build a history from rent, utility and insurance payments. The [DTI guide](https://mail.mortgage-math-us.com/buying/debt-to-income/) covers how each debt is counted.

## Sources

- [Fannie Mae Selling Guide B3-6-02](https://selling-guide.fanniemae.com/sel/b3-6-02/debt-income-ratios) — Fannie Mae maximum DTI, manually underwritten loans; Fannie Mae maximum DTI, manual underwriting with strong credit and reserves; Fannie Mae maximum DTI, Desktop Underwriter loans (Apr 2, 2025)
- [HUD Mortgagee Letter 2026-11](https://www.hud.gov/sites/default/files/hudclips/documents/2026-11hsgml.pdf) — FHA manual underwriting debt-to-income ratio (no compensating factors); FHA manual underwriting housing ratio (no compensating factors); FHA minimum decision credit score (90% LTV cap from 500 to 579) (Oct 8, 2026)
- [Fannie Mae Selling Guide B3-5.1-01](https://selling-guide.fanniemae.com/sel/b3-5.1-01/general-requirements-credit-scores) — Fannie Mae minimum score, manually underwritten fixed-rate loans (Apr 22, 2026)
- [Fannie Mae Eligibility Matrix](https://singlefamily.fanniemae.com/media/20786/display)

_General information, not financial advice._