An interest reserve is a portion of loan proceeds set aside at closing to cover the borrower’s monthly interest payments during a period when the property is not generating income. This is common on construction loans, bridge loans, and fix and flip loans where the property needs work before it can produce cash flow. Therefore, the reserve ensures the loan stays current without requiring the borrower to make payments out of pocket during the project.
How an Interest Reserve Works #
When a lender establishes an interest reserve, the lender holds the funds in a dedicated account. Each month, the lender draws from that account to cover the borrower’s interest payment. This process continues until the reserve runs out. Alternatively, it continues until the project reaches completion or the loan pays off through a sale or refinance.
The lender funds the reserve from the loan proceeds at closing. This means it is built into the total loan amount. The borrower does not deposit additional cash to fund it separately. However, because the reserve is part of the loan, the borrower must still repay it along with the rest of the balance.
When Lenders Use an Interest Reserve #
Interest reserves are most common in loan types where the property will not produce income during all or part of the loan term: Construction loans, where the property is being built and has no tenants Fix and flip loans, where the property is under renovation and not generating rent Bridge loans, where the investor may be stabilizing or repositioning the property before refinancing In each of these situations, the borrower would otherwise need to make monthly payments from personal funds while the property is not producing income. The interest reserve solves that cash flow gap.
What Borrowers Should Know About an Interest Reserve #
There are several practical considerations to keep in mind:
- The lender includes the interest reserve in the total loan balance, so interest accrues on those funds as well
- If the project takes longer than expected, the reserve may run out before the loan pays off, and the borrower becomes responsible for making payments directly
- On construction loans where the lender disburses funds in stages, interest typically accrues only on the amount drawn, not the full loan amount
- The size of the reserve depends on the loan amount, interest rate, and expected project duration
Additionally, the lender typically credits any unused portion of the interest reserve back to the borrower at loan payoff. This means if your project finishes ahead of schedule, you benefit from the shorter timeline.
Common Mistakes With Interest Reserves #
Borrowers sometimes misunderstand how interest reserves work:
- Assuming the reserve is free money rather than part of the loan that the borrower must repay
- Underestimating the project timeline, which causes the reserve to run out early
- Not factoring the reserve into the total cost of the project when calculating returns
- Confusing interest reserves with interest-only payment structures, which are related but different concepts
Summary #
An interest reserve covers your monthly interest payments during the period when a property is not producing income. In short, it is a common feature on construction, fix and flip, and bridge loans that keeps your payments current while the project is underway. As a result, knowing how the reserve is funded, how it depletes over time, and what happens when it runs out helps you plan your project budget. This understanding also helps you avoid unexpected carrying costs before your exit.