Structuring for your second, third and fourth property
Why the setup of loan one decides whether loan four happens.
Short answer
Most investors stall at one or two properties. Usually it is not income; it is structure.
Avoid cross-collateralisation
Keep each property securing its own loan. It gives you control over sales, refinances and lender choice.
Sequence your lenders
Use the lenders with the strictest policy early and keep the more generous ones for later purchases.
Keep deductible and non-deductible debt separate
Use offset accounts and separate splits so your accountant can see clearly what is claimable.