A warehouse line of credit is a short-term, revolving credit facility that a mortgage originator uses to fund home loans at the closing table before selling those loans to a permanent investor. The originator draws just enough to close each mortgage, holds the loan for days or a few weeks, sells it on the secondary market, repays the draw, and starts the cycle again. Most independent mortgage companies rely on this financing because they don’t take consumer deposits the way a traditional bank does, so without a warehouse line they couldn’t fund a single loan.
Who Provides the Line and Who Uses It
Warehouse lines are extended by large commercial banks, investment banks, and specialized lending institutions. The borrower is almost always a non-bank mortgage company, sometimes called a mortgage banker or correspondent lender, that depends entirely on outside capital to fund the mortgages it originates.
Credit limits are set based on the originator’s financial health, management track record, and expected loan production. A single mortgage company often maintains lines with several warehouse lenders at once so it always has capacity to fund the next closing.
Committed vs. Uncommitted Facilities
A committed facility is a firm promise from the warehouse lender 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; fees are often lower, but the originator carries more risk. Most originators prefer committed lines, particularly in volatile markets when lenders may pull back.
The Funding Cycle: Draw, Collateral, Takeout
Every warehouse transaction runs the same tight loop, and understanding that loop is the whole point of understanding the product.
Drawing Funds to Close
When a mortgage originator is ready to close a loan 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 it to the seller (or to the existing lender in a refinance). The new mortgage now sits on the originator’s books as an asset, financed by the warehouse line. Interest on the drawn amount starts accruing immediately.
The stretch between funding and sale is called dwell time. Originators push hard to keep it short, because every extra day of interest eats into the spread on the loan. In some market conditions the net spread per loan after warehouse carrying costs runs to just a few dollars.
Collateral and Custody
The promissory note the borrower signs, along with the associated loan documents, serves as collateral for the warehouse draw. Those documents don’t stay with the originator. They go to an independent document custodian, often a large bank, that holds them for the warehouse lender. The custodial arrangement protects the warehouse lender’s security interest and stops the originator from pledging the same loan to more than one lender.
The warehouse lender does not advance the full face value of the loan. It applies a haircut, advancing perhaps 97% or 98% of the loan amount, and the originator covers the rest from its own working capital. That margin creates a buffer against any drop in the loan’s market value between funding and sale.
When Fannie Mae buys 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 has to 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
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 buyer of 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 capacity on the line is immediately available for the next loan.
When a takeout stalls, the warehouse lender has several fallbacks. The originator can be required to repurchase the loan off the line. The warehouse lender can sell it to a different investor, sometimes one that specializes in imperfect “scratch and dent” loans at a discount. The warehouse lender can also take the loan into its own mortgage portfolio and collect the borrower’s monthly payments directly. Foreclosure on the underlying property is the last backstop and is rare.2Mortgage Bankers Association. Warehouse Lending Fact Sheet
Wet Funding vs. Dry Funding
How a warehouse draw actually works at the closing table depends on whether the transaction is wet-funded or dry-funded.
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 table, and the warehouse 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. Safer for the warehouse lender, but the closing gets pushed by a day or more.
Several states require dry funding or “good funds” procedures by law, including Arizona, California, Colorado, Idaho, New York, and Washington, among others. Originators working across state lines have to know which model each state requires, because a wet-funded closing in a dry-funding state creates a compliance violation.
What It Costs
Warehouse lines are priced as a floating rate: a spread added to a benchmark. Since the industry’s move off LIBOR, that benchmark is the Secured Overnight Financing Rate (SOFR). As of early 2026, the average effective spread above overnight SOFR for warehouse lines was around 2.45%, producing an all-in warehouse cost near 6.12%.
The carrying cost matters because it eats directly into the originator’s profit on every loan. When the note rate on a mortgage is close to the warehouse carrying cost, as it has been recently, the originator makes almost nothing on the carry itself and depends on origination fees and servicing rights for profit.
Interest is not the only cost. Warehouse lines carry several recurring fees:
- A commitment fee, charged upfront or annually on a committed facility, compensates the warehouse lender for reserving capacity.
- A non-utilization fee applies when the originator uses less than about half of the line’s capacity. It commonly runs 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 files.
This is why originators obsess over 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 market-risk feature that catches some originators off guard, especially when interest rates rise. When rates climb, the market value of existing mortgages drops because investors can buy newly originated loans at higher yields. If the loans on the 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 A margin call requires immediate cash, and thin liquidity can force an originator to sell loans at a steep discount just to meet the call. Warehouse lenders can also reduce or cancel lines outright, which can force an originator to stop funding new loans overnight. The 2022–2023 rate spike put this dynamic on full display as warehouse capacity tightened across the industry.
Digital Custody and eNotes
The old model of shipping paper promissory notes to a custodial bank is giving way to electronic alternatives. An eNote is a digital promissory note, created as a legally enforceable electronic document that can be registered, transferred, and stored in an eVault. The MERS eRegistry is the national system of record identifying who controls a registered eNote and where the authoritative copy is stored, and warehouse lenders, servicers, investors, and custodians all integrate with it.4ICE Mortgage Technology. MERS eNote Solutions When a loan sells, control transfers electronically instead of through physical shipment, which can cut days off dwell time. Fannie Mae and Freddie Mac both accept eNote deliveries.
How It Differs From a Regular Business Line of Credit
A warehouse line looks nothing like the business line of credit a company might use for payroll or inventory, and confusing the two leads to a fundamental misunderstanding of how mortgage companies are financed.
A standard commercial line of credit is general-purpose. The borrower draws for whatever the business needs, repays on a flexible schedule, and the lender takes a blanket lien on all business assets. Repayment comes from 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, not 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.
Who Can Get One
Approval for a warehouse line is considerably harder than for a typical business loan. The warehouse lender is trusting the originator to create high-quality collateral, because every loan funded on the line has to be sellable on the secondary market or the lender is stuck holding it. Underwriting focuses on operational competence, not just the balance sheet.
Warehouse lenders set minimum net worth thresholds, with a meaningful portion required in unrestricted liquid assets, and those minimums cannot fall below what the originator’s state licensing authority or its secondary market investors require. Some warehouse lenders set their floor as low as $75,000 for smaller originators; lenders working with Fannie Mae or Freddie Mac sellers often require substantially more. Beyond net worth, warehouse lenders look at monthly origination volume, the mortgage banking experience of the principal officers, compliance history under the Truth in Lending Act (Regulation Z) and the Real Estate Settlement Procedures Act (Regulation X),5Consumer Financial Protection Bureau. 12 CFR Part 1026 – Truth in Lending (Regulation Z)6Consumer Financial Protection Bureau. 12 CFR Part 1024 – Real Estate Settlement Procedures Act (Regulation X) and established agreements with secondary market investors to purchase the originator’s loans. Without confirmed takeout partners, the warehouse lender has no confidence the loans will actually sell.
The relationship doesn’t end at approval. Warehouse lenders audit the quality of loans on the line, verify that takeouts happen on schedule, and can tighten terms or reduce capacity if the originator’s performance deteriorates.