Seisin

Tenancy records for macOS.

Seisin is a native Mac app for small Australian landlords. It keeps the records a tenancy generates — rent, expenses, inspections, bonds, the compliance dates NSW law cares about — in one place, so nothing depends on a spreadsheet or memory.

I built it to manage my own rentals. There are no accounts and no service behind it: your records live on your Mac and in your own iCloud, nowhere else.

You're welcome to use it — email me and I'll sort you out with a copy. You can read about the features, how the data fits together, and the common workflows.

What it keeps track of

• Rent schedules, payments, and receipts
• Expenses and Australian financial-year summaries
• Inspections and annual smoke-alarm checks
• Bonds and their lodgement deadlines
• NSW notice periods, pet requests, and rent-increase rules
• Water usage charges, maintenance, and tenant communications

Seisin is beta software and isn't legal, tax, or financial advice — see the terms of use.