Guides / How to build

How to Build a Property Management App: Units, Tenants, Rent and Maintenance

Build a property management app for landlords or small agencies: units, leases, a rent ledger, maintenance requests, documents and a tenant portal.

Mythex Team · 2026-09-29 · 5 min read

A property management app keeps track of your properties and units, who lives in each one, what rent is due and paid, and what needs fixing. For a small landlord it replaces a spreadsheet, a folder of leases and a stream of text messages. For an agency it adds owners, staff roles and reports. The core is simple — units, leases, a rent ledger and maintenance requests — so build that first, use it for a couple of rent cycles, and only then add a tenant portal or online payments.

This guide is about the software. Rent, deposits, notices and tenant data are governed by local law; check your obligations with a local adviser.

Who is it for?

What a property management app needs

Pages

• Dashboard — rent due this month, overdue balances, open maintenance requests, leases ending soon, vacant units.
• Properties and units — address, unit details, photos, current tenant, lease, status.
• Tenants — contact details, lease history, balance, documents.
• Leases — start and end dates, rent amount and due day, deposit, terms, attached signed document.
• Rent ledger — charges and payments per lease, running balance.
• Maintenance — requests with photos, priority, status, assigned vendor, cost.
• Documents — leases, inspection reports, certificates, with expiry reminders.
• For agencies — owners, owner statements, staff and vendors.

Data

• Properties and units (a house is a property with one unit).
• Tenants — people, and optionally a tenancy linking several tenants to one lease.
• Leases — unit, tenants, start, end, rent amount, frequency, due day, deposit amount, status.
• Ledger entries — lease, date, type (rent charge, late fee, payment, credit, deposit), amount in integer cents, reference.
• Maintenance requests — unit, reporter, description, photos, priority, status, vendor, cost, dates.
• Vendors — trade, contact, rates.
• Documents — linked to a property, unit, lease or tenant, with type and expiry date.
• Owners (agencies) — which properties they own and their management fee.

Model rent as a ledger — charges and payments as separate entries — rather than a "paid" checkbox per month. A ledger handles partial payments, late fees and credits, and the balance is always the sum of entries.

Permissions

• Landlord or admin — everything.
• Staff — the properties assigned to them.
• Owners (agencies) — read-only view of their own properties and statements.
• Tenants — their own lease, balance, documents and maintenance requests, nothing else.
• Vendors (optional) — only the jobs assigned to them.

Tenant and owner portals are where data leaks happen. Every request must check that the record belongs to the person asking. See our client portal guide for how portals are usually structured.

Decisions and trade-offs

Record payments or collect them. Recording payments that arrive by bank transfer is simple and costs nothing. Collecting rent online through a provider such as Stripe is convenient for tenants but adds fees, failed payments, refunds and reconciliation. Start by recording; see how to add payments to your app when you're ready.

Automatic rent charges. Creating each month's rent charge automatically needs something that runs on a schedule. Simpler options: generate the next charges when someone opens the dashboard, or a "create this month's charges" button.

Tenant portal now or later. For a handful of units, email and a shared maintenance form are enough. A portal pays off as the portfolio grows.

Document storage. Leases and ID documents are sensitive. Store them privately, give links that expire, and keep only what you need.

Maintenance intake. A simple public form per property ("report a problem" with photo upload) works well before a full portal exists.

Example first prompt

Build a property management web app for a landlord with 12 units across 4 buildings. I manage properties and units (address, bedrooms, photos, status: occupied, vacant, under repair), tenants (name, phone, email), and leases (unit, tenants, start and end date, monthly rent, due day, deposit). Rent is a ledger: each month has a rent charge, and I record payments (date, amount, method, reference), partial payments, late fees and credits; show each lease's running balance. Store money as integer cents. The dashboard shows rent due and overdue this month, open maintenance requests, leases ending in the next 60 days and vacant units. Maintenance requests have unit, description, photos, priority, status, vendor and cost; each property gets a public "report a problem" form with photo upload that creates a request. Store signed leases and certificates privately with expiry dates and show upcoming expiries on the dashboard. Only I can log in for now, with email and password. Database and private file storage. Seed sample data.

Build steps

1. Properties, units and leases with sample data. Check the dashboard shows the right units as vacant and leases ending soon.
2. Rent ledger. Record a partial payment, a late fee and a credit, and check the balances by hand.
3. Maintenance requests and the public form. Submit one from a phone with a photo. See how to add file uploads to your app.
4. Documents. Upload a lease and confirm the file isn't reachable without logging in.
5. Reports. Rent collected per month, arrears, maintenance cost per property. Export as CSV for your accountant.
6. Staff or owner roles (agencies). Test that an owner sees only their own properties.
7. Tenant portal (later). Balance, documents, maintenance requests, and one tenant never seeing another's data.
8. Online rent collection (later).

Common mistakes

• A "paid" checkbox instead of a ledger. It can't handle partial payments, fees or credits.
• Floating-point money. Use integer cents.
• Public document links. Leases and IDs must stay private.
• Deleting old leases and tenants. Keep history; mark as ended.
• Hard-coding one country's rules. Deposit handling, notice periods and late fees vary; keep them as settings.
• Building the tenant portal first. Get your own workflow right before adding logins for others.
• No backup plan. This is data you can't lose; know how it's backed up and exported.

When property management software is better

Established property management platforms include online rent collection, tenant screening, accounting, owner payouts, e-signatures and legal forms for specific regions. If you manage many units, handle client money for owners, or need regulated trust accounting, those products carry responsibilities you shouldn't rebuild yourself.

Build your own when you have a small portfolio and want a tool that fits how you work, when per-unit pricing adds up, when you manage an unusual mix (mixed-use buildings, storage units, parking), or when you want maintenance and tenant data tied to your own systems such as a CRM.

Building it with Mythex

Mythex can build the app in the prompt above: describe it in chat, check it in the live preview, and publish it. It adds a dedicated Postgres database and file storage for photos and documents when the app needs them. Login for you, staff and later tenants is bring-your-own, and online rent collection means connecting your own payment provider's keys as project secrets; Mythex has no built-in payments or e-signature for your app. For monthly rent charges, start with one of the simpler options above rather than a scheduled job. For more starting points, browse the app templates.