A warehouse line of credit is a short-term, revolving credit facility that a mortgage originator uses to fund home loans at closing and then repay once each loan is sold on the secondary market. It works like a temporary bankroll: the originator draws just enough to close a mortgage, holds the loan briefly, sells it to an investor such as Fannie Mae or Freddie Mac, repays the drawn amount with interest, and immediately draws again for the next closing. Independent mortgage companies rely on this financing because, unlike traditional banks, they don’t hold consumer deposits to lend from.
The line is provided by a large commercial bank, investment bank, or specialized lending institution. Credit limits are set based on the originator’s financial health, management track record, and expected loan volume, and a single mortgage company often maintains lines with several warehouse lenders at once to make sure it always has capacity to fund new loans. A committed facility is a firm promise to make funds available up to the credit limit for a set period; an uncommitted facility lets the warehouse lender decline any individual funding request. Most originators prefer committed lines, especially when markets turn volatile.
How the Funding Cycle Works
Every warehouse transaction follows the same tight loop: draw, hold, sell, repay, repeat. The whole model runs on speed, because every day a loan sits on the line costs the originator interest.
Drawing Funds to Close the Loan
When a mortgage originator is ready to close with a homebuyer, it submits a funding request to the warehouse lender, usually through an electronic platform. The warehouse lender wires the exact loan amount, and the closing agent disburses the money to the home seller or, in a refinance, to the existing lender. At that moment, the new mortgage sits on the originator’s books as an asset financed by the warehouse line, and interest on the drawn amount begins accruing immediately.
The time between funding and sale is called dwell time. Originators have a strong incentive to keep it short, because the net spread per loan after warehouse carrying costs can be razor-thin in some market conditions — a few dollars per loan.
Collateral and Custody
The borrower’s promissory note and the associated loan documents serve as collateral for the warehouse draw. These documents don’t stay with the originator. They go to an independent document custodian, often a large bank, that holds them on behalf of the warehouse lender. The arrangement protects the warehouse lender’s security interest and prevents the originator from pledging the same loan to more than one lender.
The warehouse lender doesn’t advance the full face value of each loan. It applies a “haircut,” advancing perhaps 97% or 98% of the loan amount and requiring the originator to cover the rest from its own working capital. That margin requirement creates a buffer against any decline in the loan’s market value before it sells.
When Fannie Mae purchases a mortgage, the seller must represent that the note is completely free of any warehouse lender’s security interest, lien, or other encumbrance. The warehouse lender’s claim must be released no later than the date Fannie Mae acquires the note, and specific delivery procedures involving bailee letters govern the handoff.1Fannie Mae. Fannie Mae Selling Guide – General Information on Whole Loan Purchasing Policies
The Takeout: Selling the Loan and Repaying the Line
The “takeout” closes the loop. The originator packages the closed loan and sells it to a permanent investor, most commonly Fannie Mae, Freddie Mac, or a private investor in mortgage-backed securities. The investor remits the purchase price, and the originator uses those proceeds to repay the warehouse lender the drawn principal plus accrued interest. The freed-up capacity on the line is then available for the next loan.
When a takeout doesn’t go smoothly, the warehouse lender has fallback options. The originator may be required to repurchase the loan off the line. The warehouse lender can also sell the loan to a different investor, sometimes one that specializes in buying imperfect or “scratch and dent” loans at a discount. If neither works, the warehouse lender can take the loan into its own mortgage portfolio and collect the borrower’s monthly payments directly. Foreclosure on the underlying property is the final backstop, but it’s rare.2Mortgage Bankers Association. Warehouse Lending Fact Sheet
Wet Funding vs. Dry Funding
How a warehouse draw works at the closing table depends on whether the transaction uses wet funding or dry funding. In a wet-funded closing, the warehouse lender wires funds before the loan documents have been fully reviewed and verified. The borrower gets the money and the seller gets paid at the closing table, but the lender is relying on the originator’s assurance that the paperwork is complete and correct. It’s faster, but it carries higher fraud and default risk because the money is out the door before anyone catches a problem.
In a dry-funded closing, the warehouse lender holds the funds until all loan documents have been reviewed and approved. Only then does the money move. This is safer for the warehouse lender and adds a layer of protection for all parties, but it delays closing by a day or more.
Several states require dry funding or “good funds” procedures by law, meaning the warehouse lender cannot disburse until verified funds are deposited. Arizona, California, Colorado, Idaho, New York, and Washington are among them, along with more than a dozen others. Originators working across state lines need to know which model each state requires, because a wet-funded closing in a dry-funding state creates a compliance violation.
What a Warehouse Line Costs
Warehouse lines are priced as a floating rate: a margin added on top of a benchmark. Since the mortgage industry’s transition away from LIBOR, the standard benchmark is the Secured Overnight Financing Rate, or SOFR. As of early 2026, the average effective spread above overnight SOFR for warehouse lines was approximately 2.45%, producing an all-in warehouse cost of around 6.12%.
That cost eats directly into the originator’s profit on every loan. When the average note rate on a mortgage sits close to the warehouse carrying cost, as it has in recent months, the originator makes almost nothing on the carry itself and depends on origination fees and servicing rights to turn a profit.
Beyond interest, warehouse lines carry fees that add up:
- A commitment fee, charged upfront or annually for a committed facility, compensates the warehouse lender for reserving capacity.
- A non-utilization fee kicks in when the originator uses too little of the line. Warehouse lenders expect roughly half of capacity to be in use, and falling below that threshold commonly triggers a fee of 25 to 50 basis points on the unused portion.
- Custodial fees are charged per loan by the independent document custodian for receiving, reviewing, and storing loan documents.
These are the costs behind the industry’s obsession with dwell time. A loan sitting on the line for 20 days costs meaningfully more than one sold in 10, and that difference compounds across hundreds of closings a month.
Margin Calls and Market Risk
Warehouse lending carries a form of market risk that catches some originators off guard during periods of rising interest rates. When rates climb, the market value of existing mortgage loans drops because investors can buy newly originated loans with higher yields. If the loans sitting on an originator’s warehouse line lose enough value, the warehouse lender can issue a margin call demanding additional collateral or cash.
Research from the Federal Reserve Bank of Richmond found that warehouse lenders can require stricter covenants on credit lines during market stress, and that mortgage servicing rights pledged as additional collateral may be repriced or the pledge arrangements cancelled following interest rate swings.3Federal Reserve Bank of Richmond. Economic Brief 2025-33 During the COVID-19 period, some warehouse lenders imposed significantly tighter terms on non-bank mortgage companies.
Smaller originators are most vulnerable here. A margin call requires immediate cash, and if liquidity reserves are thin, the originator may be forced to sell loans at a steep discount just to meet the call. Warehouse lenders can also reduce or cancel lines entirely, which can force an originator to stop funding new loans overnight. The 2022-2023 rate spike pushed several non-bank lenders into financial distress when warehouse capacity tightened across the industry.
Qualifying for a Warehouse Line
Getting approved is considerably harder than securing a typical business loan. Warehouse lenders are trusting the originator to create high-quality collateral: every loan funded with the line must be sellable on the secondary market, or the lender is stuck holding it. Underwriting focuses intensely on operational competence, not just the balance sheet.
Financial requirements come first. Warehouse lenders set minimum net worth thresholds, with a significant portion required in unrestricted liquid assets. The specific minimums vary, but they can’t be lower than what the originator’s state licensing authority or secondary market investors require. Some warehouse lenders set their floor as low as $75,000 for smaller originators, while lenders working with Fannie Mae or Freddie Mac sellers often require substantially more.
Warehouse lenders also evaluate:
- Origination volume, meaning a minimum monthly production level that proves the originator generates enough business to justify the line and keep dwell times short.
- Management experience, with principal officers expected to show a demonstrated track record in mortgage banking, including underwriting, closing, and secondary market sales.
- Compliance history, including all required state and federal licenses in good standing and no recent enforcement actions. Warehouse lenders verify compliance with the Truth in Lending Act, implemented by Regulation Z, and the Real Estate Settlement Procedures Act, implemented by Regulation X.4Consumer Financial Protection Bureau. 12 CFR Part 1026 – Truth in Lending (Regulation Z)5Consumer Financial Protection Bureau. 12 CFR Part 1024 – Real Estate Settlement Procedures Act (Regulation X)
- Investor relationships, with established agreements in place for secondary market investors to purchase the originator’s loans. Without confirmed takeout partners, the warehouse lender has no confidence the loans will sell.
Approval is not the end of the scrutiny. Warehouse lenders audit the quality of loans on the line, verify that takeouts are happening on schedule, and can tighten terms or reduce capacity if the originator’s performance slips.
How It Differs From a Standard Business Line of Credit
A warehouse line looks nothing like the business line of credit a company might use for payroll or inventory. A standard commercial line is general-purpose: the borrower draws funds for whatever the business needs, repays on a flexible schedule, and the lender takes a blanket lien on all business assets as security. Repayment comes from the company’s overall cash flow.
A warehouse line is asset-specific. Every draw is tied to a particular mortgage loan, and repayment comes from the sale of that specific loan rather than from general business revenue. The collateral is the individual promissory note and its associated documents, not a blanket claim on everything the company owns. The warehouse lender’s security interest in each note must be fully released when the loan sells to the permanent investor.1Fannie Mae. Fannie Mae Selling Guide – General Information on Whole Loan Purchasing Policies
Warehouse lines also tend to involve limited-recourse provisions. If a loan can’t be sold and the originator can’t repurchase it, the warehouse lender’s primary recovery comes from the collateral itself rather than from a claim against all of the originator’s assets. Standard commercial lines are typically full recourse, giving the lender the right to pursue any business asset and sometimes the personal assets of the owners. For mortgage companies, that distinction shapes how they manage risk and how they structure their balance sheets.