Interest-Only vs Principal & Interest for an Investment Property
Published
Written by Lindsay Hill · Relationship Manager — Mortgages, Orange Network
Reviewed by Chad Weber · Head of Lending
Choose interest-only on an investment property when cash flow is the priority and you have a clear reason to keep repayments low for a defined period — for example while you renovate, hold a property you intend to sell, or direct spare cash at other debt. Choose principal and interest when the goal is to own the property outright over time and you do not want a larger repayment landing later. Interest-only does not make the loan cheaper. It makes it cheaper now and leaves the whole debt where it started, with a bigger repayment waiting when the interest-only period ends.
What interest-only actually means
For the interest-only period — often one to five years at a time, subject to the lender's policy — your repayment covers only the interest. The balance does not move. When the period ends, the loan flips to principal and interest over the remaining term, and the repayment steps up, sometimes sharply, because the same debt now has fewer years to clear. Lenders assess whether you can afford that higher repayment from the start, not just the interest-only one.
The case for each
- Interest-only: lower repayments improve rental cash flow month to month, which can matter when rates, insurance, and maintenance are rising
- Interest-only: frees cash to repay non-deductible or higher-cost debt first — a strategy to run past your accountant, because the tax treatment of investment interest has changed more than once
- Principal and interest: every repayment reduces the debt, so equity builds from repayments as well as from the property's value
- Principal and interest: no repayment shock at the end of an interest-only term, and a smaller loan when you come to refinance or sell
What lenders look at
Not every lender offers the same interest-only terms, and how much rent a lender will count — they shade it, they do not take the full weekly figure — differs between them. Your own home loan, other rentals, and the equity across the portfolio all sit in the same servicing test. If the numbers only work interest-only at one lender, that is worth knowing before you buy, not after.
A practical way to decide
Start with the exit, not the repayment. If this is a long-term hold and retirement income is the point, principal and interest is usually doing the real work. If it is a short-to-medium hold, a renovation, or a stepping stone to the next purchase, an interest-only period can be the right tool — with the end date and the higher repayment written into the plan from day one. Either way, model both. We run interest-only and principal-and-interest side by side across lenders, and your accountant owns the tax side of the decision. This is general information, not personalised financial advice. FSP665511.
