Rate Lock: How to Secure Your Home Loan Rate Before Settlement

What a rate lock does

Fixed rates can change right up until your loan is funded. When you choose a fixed rate, lenders generally apply the fixed rate available at settlement, not the one advertised when you applied. Between application and settlement, often six weeks or more, that rate can move.

A rate lock holds the current fixed rate for a set period in exchange for a fee. It’s for fixed rates only, because a variable rate can change at any time.

Lenders reprice fixed rates on their own schedule, and fixed rates can move even when the Reserve Bank leaves the cash rate unchanged. That’s the risk a lock removes.

Rate locks on split loans

If you split your loan, for example $500,000 fixed and $200,000 variable, the lock applies to the fixed part only. Check how the fee is charged: CommBank charges its fee per fixed rate loan account, so two fixed splits mean two fees.

How much a rate lock costs and how long it lasts

Each lender sets its own terms. Here’s what four lenders published when we checked in September 2026.

What happens if rates fall, or settlement is late

• If fixed rates fall before settlement. NAB and Bank of Melbourne say you get the lower rate. CommBank doesn’t pass it on automatically, but you can ask to break the lock and take the rate on the funding date. The fee isn’t refunded either way.
• If settlement runs past the lock. The lock expires and the fixed rate on the day of settlement applies. NAB still charges the fee. CommBank won’t extend a lock, but you can take a new one at current rates for another fee.
• If you change fixed term. At CommBank, locking a different term means a second fee.

When a rate lock is worth it

A lock tends to be worth it when:

• you’re sure you want to fix all or part of the loan
• settlement is likely to fall inside the lock period
• a higher rate before settlement would stretch your budget
• the fee is small next to what a rate rise would cost you.

It’s usually not worth it if you might choose a variable rate after all, if settlement is months away (an off-the-plan purchase that completes long after 90 days, for example), or if your lender won’t pass on a lower rate and you think fixed rates may fall.

How to lock your rate

1. 1

   Decide whether to fix

   Weigh certainty against flexibility first. Our guide to fixed or variable home loans walks through it.

2. 2

   Compare lock terms, not just the rate

   Check the fee, the lock period, when it starts and what happens if rates fall.

3. 3

   Request the lock early

   NAB suggests requesting it with your application, though you can lock any time before drawdown. CommBank locks can be requested until loan documents are issued.

4. 4

   Match the lock to your settlement date

   Count 90 days from the actual start date and compare it with the completion date in your contract.

5. 5

   Keep settlement on track

   Return loan documents quickly and keep your conveyancer and lender in touch.

Still house hunting? Start with our guide to home loan pre-approval.

Remember what fixing means

A rate lock protects the rate you fix at. It doesn’t change how fixed loans work. Moneysmart notes that a fixed rate protects you from rises, but you won’t benefit if rates fall during the fixed term.

Before you fix, ask about break costs if you repay early, sell or refinance, limits on extra repayments, and whether an offset account is available. Compare repayments at different rates in our home loan repayments calculator, and if you’re thinking about switching lenders later, read how to refinance a home loan or see how we help with refinancing.

Frequently asked questions

Can I lock a variable interest rate?

No. Rate locks are for fixed rates. A variable rate can change at any time, including after settlement, so there’s nothing to lock. If you split your loan between fixed and variable, the lock applies to the fixed part. Some lenders limit when you can lock: CommBank, for example, offers it only on new loan applications.

Is the rate lock fee refundable?

Generally not. CommBank and NAB both describe their rate lock fees as non-refundable, and NAB says the fee is still payable if your loan settles after the lock period ends. Treat the fee as the cost of certainty, and only lock when you’re confident you’ll go ahead with that fixed loan.

How long does a rate lock last?

At the lenders we checked in September 2026, locks last up to 90 days. When the 90 days start differs: from when the lock request is processed, from when you lock, or from when the lender receives your signed loan agreement. Check the start date against your settlement date before you pay.

What happens if settlement is delayed past my rate lock?

The lock expires and the lender applies its fixed rate on the day of settlement, which could be higher or lower. At NAB the rate lock fee is still payable. CommBank doesn’t extend a lock, but you can take out a new one at current rates for another fee. If a delay looks likely, talk to your broker early.

If rates drop after I lock, do I get the lower rate?

It depends on the lender. NAB and Bank of Melbourne say you’ll get the lower fixed rate if it has fallen by settlement. CommBank doesn’t pass it on automatically, but you can ask to break the lock and take the rate on the funding date, without a refund of the fee. Check this before you lock.

Sources

1. Commonwealth Bank: Rate Lock request form and terms (opens in a new tab)
2. ANZ: Fixed rate home loan (rate lock) (opens in a new tab)
3. NAB: Rate Lock (opens in a new tab)
4. Bank of Melbourne: Home loan rate lock (opens in a new tab)
5. Moneysmart: Choosing a home loan (opens in a new tab)
6. Moneysmart: Fixed rate home loan (opens in a new tab)