Glossary term
London Interbank Offered Rate (LIBOR)
LIBOR was a benchmark interest rate once used across loans, derivatives, and other financial contracts, now largely replaced by alternative reference rates such as SOFR.
Updated
Read time
What Was LIBOR?
London Interbank Offered Rate, usually called LIBOR, was a benchmark interest rate meant to reflect what major global banks would charge one another for short-term unsecured borrowing. For decades, it appeared in adjustable-rate loans, floating-rate bonds, derivatives, business credit agreements, and some consumer contracts.
LIBOR is mostly important today because it was phased out and replaced in many U.S. dollar contracts by rates based on SOFR, the Secured Overnight Financing Rate. Older documents may still mention LIBOR, but new financial products generally should not rely on it as the active benchmark.
Key Takeaways
- LIBOR was a reference rate used to set interest on many floating-rate financial contracts.
- It was published in different currencies and borrowing periods, such as one-month or three-month U.S. dollar LIBOR.
- The benchmark was phased out after concerns about reliability, market depth, and manipulation.
- Many U.S. contracts moved to SOFR-based replacement rates after the transition.
Where LIBOR Showed Up
A benchmark rate gives a contract a moving base rate. A loan might charge LIBOR plus a fixed spread, meaning the borrower paid the benchmark rate plus an added margin for credit risk and lender profit. When LIBOR rose, the interest cost rose. When it fell, the cost generally fell too.
Use | How LIBOR Affected Cost or Value |
|---|---|
Adjustable-rate loans | Helped set the interest rate after each reset period. |
Floating-rate bonds | Helped determine coupon payments to investors. |
Derivatives | Served as a reference rate for swaps and other contracts. |
Business credit lines | Often acted as the base rate before a credit spread was added. |
The Transition Away From LIBOR
LIBOR depended partly on bank submissions rather than a deep base of actual transactions in every tenor and currency. After the financial crisis and benchmark-manipulation scandals, regulators pushed markets toward rates built on more observable transaction data. In the United States, SOFR became the main replacement reference rate for many dollar contracts.
The transition matters most for people and businesses reviewing older contracts. A legacy agreement may describe a fallback rate, replacement index, spread adjustment, or amendment process. The practical question is not only what LIBOR was, but what the contract uses now that LIBOR is no longer the normal operating benchmark.
What to Check in an Older Contract
Look for the benchmark, reset frequency, margin, fallback language, and notice requirements. A contract that once referenced three-month LIBOR may now reference a SOFR-based rate plus an adjustment. The replacement language can affect monthly payments, interest income, valuation, or hedging results.
The Bottom Line
LIBOR was once one of the world’s most important interest-rate benchmarks, but it has largely been retired. Its remaining relevance is practical: older loans, bonds, and financial agreements may still contain LIBOR language, so readers need to understand how the replacement rate now determines cost, income, or value.