BBSW: The Benchmark Behind Business Lending

Key takeaways

• BBSW is a bank funding benchmark, not the RBA cash rate.
• Commercial loans are commonly priced as BBSW plus a credit margin.
• The gap between BBSW and the cash rate widens when funding stress rises.
• Ask which tenor of BBSW your facility uses - 30, 90 or 180 day.

What is BBSW and who sets it?

BBSW is the benchmark interest rate for short-term bank paper in Australia, administered by ASX Benchmarks. It is calculated from transactions in the bank bill and negotiable certificate of deposit market across standard tenors, most commonly 30, 90 and 180 days.

It represents what banks pay to borrow from each other at short maturities. That makes it fundamentally a funding cost measure, which is why it does not simply equal the cash rate.

Following global benchmark reform, BBSW is calculated from observable transactions rather than from panel submissions, which is what distinguishes it from the discredited pre-reform LIBOR methodology.

Why does BBSW move apart from the cash rate?

The cash rate is the overnight rate the RBA targets. BBSW is a term rate covering weeks or months, so it embeds two things the overnight rate does not: expectations about where the cash rate is heading over that term, and a premium for bank credit and liquidity risk.

For a borrower on a BBSW-linked facility this matters directly: your rate can rise even in a month when the RBA does nothing, because the benchmark itself moved.

How does this show up in a commercial loan?

A commercial facility is usually quoted as "BBSW plus X%", where X is the credit margin for your business, your security and your leverage. The benchmark resets at each interest period - so a 90-day BBSW facility reprices quarterly.

Three questions worth asking your lender before signing:

1. Which tenor resets your rate, and how often? A 30-day reset passes market moves through four times faster than a 180-day one.
2. Is there a floor on the benchmark? Some facilities floor BBSW at zero or above, which matters if rates fall.
3. What is the margin, separately stated? The margin is the negotiable part. The benchmark is not.

Home loans work differently - Australian variable home loans are priced off each lender's own standard variable rate, which the lender adjusts with reference to the cash rate and its overall funding costs rather than being contractually linked to BBSW.

Frequently asked questions

What does BBSW stand for?

Bank Bill Swap Rate. It is the benchmark short-term interest rate for Australian bank paper, administered by ASX Benchmarks and calculated from observable market transactions across standard tenors.

Is BBSW the same as the cash rate?

No. The cash rate is the RBA's overnight target. BBSW is a term rate over 30 to 180 days that includes expectations of future cash rate moves plus a bank credit and liquidity premium, so the two move differently.

Do home loans use BBSW?

Generally not directly. Australian variable home loans are priced off the lender's own variable rate, which the lender sets with reference to the cash rate and its blended funding costs. BBSW is more common in business, commercial and institutional lending.

Can my BBSW-linked rate rise if the RBA does nothing?

Yes. If bank funding costs rise or the market prices in future increases, BBSW can move independently of the cash rate, and your facility reprices at the next reset.

Related reading

• How Swap Rates Determine Your Fixed Home Loan Rate
• Where Banks Actually Get the Money They Lend You
• Business Loan Types: A Complete Australian Guide

Sources

• BBSW benchmark methodology — ASX Benchmarks
• The Australian money market — Reserve Bank of Australia