Setting up mortgages and bank accounts

Prop Insights can model your mortgages and bank accounts as loosely or as precisely as you like. A property with no linked accounts still gets a full forecast — it’s just based on the loan terms you entered when you added the property (purchase price, deposit, rate, term). Linking real accounts switches individual figures over to your account’s actual balance, repayment schedule, and any offset — without you having to re-enter anything the property already knows.

This guide covers four setups, from simplest to most involved.

1. Simple: one mortgage, one transaction account

The most common setup for a single property.

1. Banks → Add account — create the mortgage: Type = Mortgage, enter the current balance and the date that balance is as of. Add the interest rate and loan type (Principal & Interest or Interest Only) so Prop Insights can project the balance forward.
2. Add a second account — Type = Transaction, with the balance the rent lands in and the mortgage repayment comes out of.
3. On the property’s own Banks tab, link both accounts to the property.
4. On the mortgage account, set “Repayment comes from” to the transaction account.

With this in place, the property’s Cashflow tab shows the mortgage’s real current balance (not just a formula projection from your original loan amount), and the transaction account’s own balance projection includes the real monthly repayment as an outflow — so a lump-sum payment or an extra repayment you’ve made shows up correctly everywhere, not just on the mortgage account’s own page.

2. Mortgage + offset account

If your loan has a linked offset account, model it as its own account rather than folding its balance into the mortgage.

1. Add the mortgage account as in Setup 1.
2. Add another account — Type = Offset, set “Offsets property” to the property whose mortgage it reduces.
3. Link the offset account to the property too (Property → Banks tab).

The property’s Cashflow tab then shows an Interest Saved card — the actual monthly interest reduction from the offset balance, reconciled against the mortgage’s real repayment (not a flat balance × rate estimate). If the offset account exists but isn’t reducing anything, a warning explains why (usually a missing or mismatched mortgage link) instead of the card just silently not appearing.

3. Just tracking cash — transaction and savings accounts

Not every account needs to be tied to a property. A transaction or savings account with no property linked still shows up under Banks with its own balance and transaction history — useful for a general savings buffer, an emergency fund, or an account you’re tracking but don’t want factored into any property’s cashflow (tick “Exclude from cashflow” on the account if you want it to count toward your dashboard’s total cash balance without affecting any property’s projections).

4. Complex: hub-and-spoke across a portfolio

Many investors run everything through one central transaction account rather than a dedicated account per property: rent from every property lands in the same hub account, and every mortgage repayment is debited from it too.

1. Add one Transaction account — this is the hub. Link it to every property in the portfolio (Property → Banks tab, for each one).
2. Add a Mortgage account per property (the spokes) — each with its own balance, rate, and repayment schedule.
3. On each mortgage account, set “Repayment comes from” to the hub transaction account.
4. Leave each mortgage account itself linked only to its own property (not to the hub) — this keeps the mortgage’s own balance/payoff figures scoped to that one loan, while the hub correctly shows every property’s repayment as a separate line in its own balance projection.

This is the setup the Cashflow Map (Dashboard → Cashflow chart, or the standalone /sankey page) is built to visualise: rent from every property flows into the hub, the hub pays out to each property’s mortgage and expenses, and if the hub can’t cover a property’s shortfall on its own, the gap shows as a Salary top-up flow. If you’ve set up a regular transfer (Banks → Transfers) into the hub to cover that gap — say, a fortnightly amount from your pay — the chart shows that transfer as its own flow instead of assuming the whole gap comes from an unmodeled salary top-up.

The Monthly Top-Up card

Any negatively-geared property’s own Cashflow tab shows a Monthly Top-Up Needed card once its net cashflow goes negative. It checks for a real transfer landing in one of the property’s own linked accounts and tells you directly whether it’s fully covered, partially covered, or not funded at all — rather than just showing the shortfall number with no context on whether you’re already handling it.

Which account fields actually drive the numbers

Field	Set on	What it changes
Account balance + balance date	Mortgage / Offset / Savings / Transaction	The starting point for every balance projection — always prefer this over the property’s original loan amount once you have a real account linked
Interest rate, loan type	Mortgage	How the balance is projected forward between now and payoff
Repayment amount / frequency	Mortgage	Used together with lump sums to project the real remaining balance, distinct from a pure amortisation formula
Lump sum payments	Mortgage	One-off extra payments — reduce the projected balance from that date onward
Repayment comes from	Mortgage	Which account’s own balance projection shows the repayment as an outflow — leave unset if the lender auto-debits from an account you don’t track
Offsets property	Offset	Which property’s mortgage interest this account’s balance reduces
Exclude from cashflow	Any	Keeps the account’s balance in your total cash figure without feeding any property’s projection

Common questions

Do I need to link every account to get accurate numbers? No — a property with no linked accounts still forecasts from its own loan terms (purchase price, deposit, rate, term). Linking real accounts only improves precision once real balances start to diverge from that original formula (extra repayments, a rate change, an offset).

What if I haven’t set “Repayment comes from” on a mortgage account? Nothing breaks — the mortgage account’s own balance and payoff projection are unaffected. The only difference is that no other account’s own balance projection shows that repayment as an outflow, since nothing is tracking where the cash actually came from.

Can one account be linked to more than one property? Yes — that’s exactly the hub-and-spoke setup in Section 4. A transaction account can be linked to as many properties as share it.