Beta Software Disclaimer

Seisin is experimental software provided for testing purposes only. It does not provide legal, tax, or financial advice. You must verify all legal requirements and calculations independently. See Terms of Use for full details.

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Seisin¶

Property management, refined.

A native macOS application for Australian landlords who value simplicity over complexity. Track rent, manage leases, and stay organised—without the enterprise bloat.

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$1,480 Weekly Income

100% Occupancy

4 Properties

A different approach¶

1

Built for individuals¶

Most property software assumes you're running an agency. Seisin assumes you're a person with a few properties and a life outside of spreadsheets.

2

Your data stays yours¶

Everything syncs via your iCloud account. No servers to trust, no subscriptions to forget, no company policies to worry about.

3

Built for Australia¶

Australian financial years (July–June), NSW tenancy law compliance, water billing, and expense categories that match ATO requirements.

4

Designed for macOS¶

Not a web app in disguise. Native performance, native keyboard shortcuts, native aesthetics. It feels like it belongs on your Mac.

Everything you need, nothing you don't¶

Dashboard at a glance¶

See what matters today. Upcoming payments, expiring leases, scheduled inspections—all surfaced automatically. No digging through menus.

Overdue payments highlighted immediately
Lease renewals flagged 60 days ahead
Inspection reminders with NSW compliance

! 2 payments overdue

i Lease expires in 14 days

✓ $8,200 collected this month

Rent and water billing¶

Create a lease, set the rent and frequency, and Seisin generates the schedule. Record water bills from your supplier and recharge usage to tenants where permitted.

Automatic payment schedule generation
Water bill recording and tenant invoicing
Full payment history per tenant

1 Jan Paid $1,500

1 Feb Paid $1,500

1 Mar Due $1,500

Reports for tax time¶

Generate Australian financial year summaries with a few clicks. Income, expenses, and property-level breakdowns ready for your accountant.

Financial year income reports (July–June)
Expense categorisation for ATO
Property performance comparisons

Q1

Q2

Q3

Q4

Complete property management¶

Properties

Address details, photos, notes, and document storage. Everything about a property in one place.

Tenants

Contact information, emergency contacts, lease history. Keep tenant records organised.

Leases

Fixed-term and periodic tenancies under NSW law. Automatic rent schedules. Bond tracking with NSW Fair Trading.

Payments

Record payments, track balances, handle partial payments. Full ledger for each lease.

Inspections

Schedule and track property inspections. Attach photos and notes. NSW law limits routine inspections to four per year.

Water & Expenses

Record water bills and generate tenant invoices. Log council rates, strata levies, repairs, and other costs. Categorise for tax time.

Rent Increases

Record rent increase history with effective dates. NSW requires 12 months between increases for periodic tenancies.

iCloud Sync

Your data syncs automatically across your devices. No manual backups needed.

Interested in Seisin?¶

This is a personal project built for my own property management needs. If you're interested in learning more or trying it out, feel free to get in touch.

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