Choosing between fixed and variable interest is mainly a decision about certainty, flexibility and your ability to absorb change. Neither structure is automatically cheaper.
What a fixed rate does
A fixed rate stays unchanged for an agreed period. Your scheduled repayments are generally predictable during that period, which can make budgeting easier.
The trade-off is that fixed loans may limit extra repayments or charge a break cost if you refinance, sell an asset or repay early. Always check what happens when the fixed period ends.
What a variable rate does
A variable rate can rise or fall in response to market conditions and the lender's pricing decisions. Your repayment may change, sometimes with relatively little notice.
Variable loans often provide more repayment flexibility, although features differ between products. A rate fall may reduce your interest cost; a rise may increase it.
Stress-test the variable option
Calculate your repayment at the quoted rate, then again at one and two percentage points higher. The difference shows the budget buffer you may need if rates rise.
Questions worth asking
- How long is the rate fixed, and what follows?
- Can I make extra repayments without a charge?
- How quickly would a variable-rate change affect my payment?
- Is a split-rate structure available and appropriate?
- Which fees differ between the options?
Match the structure to your cash-flow resilience and likely plans, not a prediction about where rates will go.