Private, open-source budgeting in the browser with end-to-end encryption
- Zero-based
- Expense tracking
- Couples & families
Zero Sum
Zero-based budgeting web and iPhone app with tiered plans and optional bank sync.
Research-based review, not hands-on testing. Last researched .
Overview
Zerosum is a zero-based budgeting app where users assign every dollar of income to categories, with savings goals, recurring transactions, loan tracking and reports. Plans are tiered by bank-sync level: manual, bring-your-own SimpleFIN/Lunch Flow, or managed sync. It is run as a personal project by one developer in Portugal.
Best for: People who want a zero-based budget, may not need bank sync, and want to pay only for the sync level they use.
Pros and cons
Pros
- Basic tier ($30/year on the web) covers manual budgeting, goals, recurring transactions, loan tracking, analytics and CSV/OFX/QFX/QIF import.
- Bank sync is optional: bring your own SimpleFIN or Lunch Flow account (Plus) or use managed sync via Plaid (US/Canada) or Lunch Flow (Pro).
- Export of CSV files, JSON backups and full account data is available on every plan.
- Vendor states data is not sold, not shared with advertisers, and not used to train AI models.
- Public roadmap, feedback board and changelog; releases are frequent (v1.9.6 to v1.10.4 between Aug 17 and Sep 28, 2026).
- Shared budgets: 1 member on Basic, 3 on Plus, 5 on Pro.
Cons
- Very new product with a short public history; App Store showed 28 ratings.
- Terms describe it as a personal project run by one person, with no uptime or support guarantee.
- Native app is iPhone only; Android, Mac and Windows use an installable web app.
- No free tier; trial requires a payment method and starts on the Pro plan.
- iOS in-app prices are higher than the website prices (e.g. Basic annual $39.99 vs $30).
- Managed bank sync is limited to Plaid in the US/Canada or Lunch Flow elsewhere.
Features
- Envelope budgeting not confirmed not confirmed
- Automatic bank sync included
- Manual transaction entry included
- Goal tracking included
- Debt payoff tools not confirmed not confirmed
- Investment tracking not confirmed not confirmed
- Bill reminders not confirmed not confirmed
- Reports & charts included
- Multi-currency not confirmed not confirmed
- Shared / household budgets included
- Separate logins for shared budgets not confirmed not confirmed
Zero-based budgeting, savings goals, recurring transactions, split transactions and transfers, loan and mortgage tracking, analytics dashboards, bank sync options, shared budgets, 17 themes
Our review
Short version
Zerosum is a zero-based budgeting app where users assign every dollar of income to categories, with savings goals, recurring transactions, loan tracking and reports. Plans are tiered by bank-sync level: manual, bring-your-own SimpleFIN/Lunch Flow, or managed sync. It is run as a personal project by one developer in Portugal.
Quick profile, not a full review. Built on 2026-09-29 from the vendor site, store listings and public sources. No hands-on testing: I did not sign up, start a trial or connect a bank.
Cost
- Web monthly prices not shown in fetched page; iOS in-app Basic monthly $5.99 (Plus $8.99, Pro $12.99)
- Web: Basic $30, Plus $50, Pro $75 per year; iOS in-app annual: Basic $39.99, Plus $59.99, Pro $89.99
- Trial: 1 month of Pro free on Pro Annual; payment method required
What is distinct
- Tiered plans priced by bank-sync level, including bring-your-own SimpleFIN/Lunch Flow sync
- Multiple tags per transaction (per vendor comparison page)
- Customizable analytics dashboard from 20+ widgets, with 16 built-in reports
- 17 color themes, each in light and dark
- Installable web app (PWA) for Android, Mac and Windows
- Auto Budget panel to fill underbudgeted categories or cover overspending
Not confirmed
Exact launch date and year; Founded year; Web monthly prices; Android/Google Play app (none found); Independent reviews outside the App Store; Debt payoff, bill reminder, investment and multi-currency support; Whether an envelope-style workflow is supported; Earliest changelog entries before Aug 17, 2026.
Notes
The website says 16 built-in reports; the App Store text says twelve.
Ratings are set separately against a shared rubric.
Zero Sum alternatives
Free web-based zero-based budgeting for manual entry, installable on phones
- Zero-based
- Expense tracking
- Forecasting
Envelope budgeting with Plaid bank sync on web and iPhone
- Envelope
- Zero-based
- Expense tracking