ZelvoZelvobeta
About

The tool I needed didn't exist.
So I built it.

Zelvo is an independent project by an Auckland-based landlord — made first for my own tax return, then shared with everyone else still doing this manually on a Saturday afternoon.

Read the story
How it started

One rental, one IR3, one lost weekend.

At a glance
Built by
Hari Maurya
Based in
Auckland, Aotearoa
Started
As a fix for my own rental

It started with my own tax return.

I own a rental in Auckland — a flatting setup, the kind where I live in the house with tenants and apportion shared costs between private use and rental use. When I sat down to file my first IR3, I went straight to the source: IRD's own guidance, the floor-area method for shared rooms, the flat 50% rule for common areas, the interest-deductibility rules. By the time I had a working spreadsheet, I'd lost most of a weekend — and realised I'd be redoing this every year, every time the rules shifted.

So I did what software engineers do when something is repetitive: I went looking for a tool. Most property-management apps don't know what flatting is. Accounting platforms are built for businesses with bookkeepers, not someone with a single rental and an IR3 to file. The rules themselves are thorough but scattered across IRD pages, accountant blogs, and the occasional Reddit thread.

I did find a community, though — landlords on Facebook groups, Reddit threads, tenancy forums, doing the same work I was: cross-referencing IRD pages, double-checking each other's deduction logic. I wasn't alone, and this wasn't a problem one more spreadsheet was going to solve.

So I built Zelvo — first for my own property, then, once it was actually saving me time, for anyone else still doing this by hand.

What it is

A focused tool for one job.

From scattered receipts to IR3-ready figures.

Zelvo is built around one purpose — getting an NZ residential landlord from scattered records to IR3-ready figures at tax time. Not a general accounting platform, not a property manager, not a bookkeeping app. Just the parts that matter when you sit down to file.

You keep transactions, receipts, room layouts, and tenancy dates in one place as the year goes by. Zelvo handles the apportionment maths — IRD's floor-area method for shared properties, full deduction for rented-only rooms, the flat 50% for common spaces — and tracks per-bedroom tenancies day-by-day for flatting setups, so partial occupancy adjusts the ratio automatically.

It also applies the niche IRD rules landlords routinely miss — capital-vs-repair classification, chattel depreciation with per-asset rates, mileage, low-value asset write-off, the legal-fees cap, and prior-year-loss reminders when ring-fencing applies. When tax time arrives, the IRD Filing page hands you IR3R figures broken down line-by-line — and for joint ownership, every figure auto-scales by percentage so each co-owner gets their own IR3-ready numbers.

That's the whole job. No invoicing, no payroll, no general-purpose accounting. Just the parts that matter when it's time to file.

How it's built

A handful of commitments.

Not a values page. Just how this project is run.

01

Tested against IRD's own examples

Every tax calculation in Zelvo is checked against the worked examples IRD publishes on its own site. When they don't match, the code changes — not the other way around.

02

Updated each fiscal year

Kilometre rates, chattel thresholds, interest-deductibility settings, depreciation rules — reviewed and updated as IRD revises them. No stale numbers quietly ageing in production.

03

Bug reports get answered

If you email about a number that looks wrong or a page that won't save, it gets read and looked into. You'll hear back from a person.

04

No quiet surprises

No retroactive paywalling of features you were already using, no quiet data collection, no dark patterns. If something changes in a way that affects you, you'll hear about it.

05

Your records are yours

Not sold. Not used to train AI. Not shared with advertisers. Delete your account and the records tied to properties only you owned are permanently gone, in the same moment.

06

Built with skin in the game

My own Auckland rental runs through this tool. If the floor-area apportionment is wrong, my IR3 is wrong too.

Being honest

What Zelvo isn't.

Boundaries, stated plainly.

  • Not a tax agent.Zelvo helps you organise records and estimate your position. It doesn't file for you, and using it doesn't create a tax-agent relationship.
  • Not a replacement for your accountant.Zelvo applies IRD's rules and organises your records, but it doesn't give personalised tax advice or judgement calls on edge cases. For advice on your specific situation — or for complex setups like trusts, look-through companies, overseas owners, or mixed-use holiday homes — work with a qualified tax professional.
  • Not data-hungry.No ads, no profile-based ad targeting, no AI training on your records, no selling your data. Basic analytics are used to understand how the app is used — details in the Privacy Policy. The business model is landlords, not advertisers.
Who it's for

Genuinely useful to some. Not everyone.

Better for a few hundred NZ landlords than vague for tens of thousands.

Built for you if…
  • ✓You're an NZ resident with one or a few residential rentals.
  • ✓You do (or want to do) your own IR3 rather than pay someone else to.
  • ✓Your setup is full-rental or flatting — the two most common NZ arrangements.
  • ✓You'd like to stop losing weekends to the same IRD calculations each year.
  • ✓You value a tool that's honest about what it does and doesn't know.
Probably not for you if…
  • —You run a property portfolio through a trust or look-through company.
  • —You have short-stay / Airbnb / mixed-use holiday-home arrangements.
  • —You're a non-resident or have overseas property.
  • —You need an enterprise-grade accounting platform with invoicing, payroll, and a practice-level GST workflow.
  • —You need a contractual SLA and a support hotline.

If Zelvo isn't the right fit, that's genuinely OK — a dedicated accounting platform or an accountant you trust will serve you better. Use the right tool for the job; that goes for this one too.

Say hi

Bug, idea, or just curious?

Every email goes to the person who built the app. If something in Zelvo is wrong, broken, or missing, that's the fastest way to have it fixed.

Open the contact form
✓Built by an NZ landlord, in Auckland✓Free for one property✓No ads, no data sold