Smarter Offsets, Splits and Repayments For Big Harbourside Loans

Large harbourside loans work best with one main offset linked to your non‑deductible home debt, a small number of clean splits for investment or business, and repayments sized off stress‑tested numbers that match when you actually get paid (salary, bonuses, dividends or distributions).

In practice, that means: (1) routing all income into a primary offset, (2) structuring splits by purpose for tax clarity, and (3) setting minimum repayments off stressed rates (current +3%) while using extra payments and offsets to smooth lumpier income.

Keep one main offset linked to your home split, with only a few clean purpose-based splits for investment or business debt.

Step 1: Decide your “safe” repayment and buffer

Before touching structure, lock in a safety line.

For Eastern Suburbs borrowers, a practical ceiling is total home + investment repayments under about 30–35% of after‑tax income when modelled at an interest rate 3% above current levels (aligns with APRA’s buffer and our other guides).

Example (harbourside couple):

• $3.5m total debt (home + 1 investment)
• Current average rate: 5.8% p.a.
• Stressed rate: 8.8% p.a. (5.8% + 3%)
• After‑tax household income: $520,000 (~$32,500/month)

At 8.8%, total P&I repayments of ~$10,000–$11,000/month (around 31–34% of income) is your red line.

You also want 3–6 months of those stressed repayments sitting in cash or offset after settlement, as we reinforce in our other harbourside pieces and broader restructuring work.

Once you know the ceiling, you can design splits and offsets that keep you safely under it.

Step 2: Map your splits by purpose (and clean them up)

With multi‑million loans, you do not want one giant, mixed‑purpose facility.

Keep splits as few as possible, but crystal clear:

1. Home split (non‑deductible)

   • Variable P&I, longest term (e.g. 25–30 years).
   • Linked to your primary offset.
   • Goal: attack this first.

2. Investment splits (potentially deductible)

   • Separate split for each major investment purpose (e.g. existing investment property, future renovation, equities if applicable).
   • Can be IO or shorter P&I term depending on strategy (see our IO vs P&I analysis in Dover Heights: /insights/structuring-large-mortgages-dover-heights-prestige-io-vs-pi).

3. Business or other purposes

   • Keep business, ATO or personal consolidation debt in their own splits.
   • Different terms are fine (e.g. a 7–10 year split for business equipment), as long as the purpose is clean.

This mirrors the approach in /insights/using-multiple-splits-offset-accounts-large-home-loan: loan purpose, not property, drives tax deductibility.

Quick structure checklist

• Any split used to buy or improve the home you live in? → label “Home – Non‑deductible”.
• Any split for investment or business? → separate split, separate label.
• Any redraw or offset blended across purposes? → high‑risk for tax; fix this.