Manage your finances and control your spending with Envelopes.
Principal Plan is developed in the U.S.A. with privacy, security and performance as top priorities. It is a native desktop application, so it works without a network connection and without waiting on a server, and your financial data is stored on your own computer rather than in a cloud account. Install it free on your PC or Mac, use it for 60 days, and if you like it, purchase an inexpensive monthly, annual or forever license.
Mobile Envelope Syncing — Now Available for Android and iOS. Principal Plan Mobile securely pairs with Principal Plan running on your desktop (Windows or Mac), so your Envelope balances go wherever you go. Your data is end-to-end encrypted on your desktop before it leaves. Get it on Google Play or get it on the App Store.
Features at a glance
Envelope based personal accounting software using an allocation model so you give every dollar a job the moment it arrives. See exactly what's available for groceries, clothing, and more—before you spend. Create a simple budget in a few minutes that you can print or export to CSV (which opens in Excel). Every Envelope, Account and report is calculated on your own machine, so you know what is available before you spend rather than after. Available in six languages: English, German, Spanish, French, Italian, and Portuguese.
Local, private, secure and fast
Not a web app — runs on your PC or Mac. No cloud account required, no sign-up, and your finances stay on your computer. Optional mobile pairing is securely encrypted end-to-end with a random key plus a passphrase you choose — the data on our servers is only readable by your desktop and mobile devices.
Envelope-first planning
Give every dollar a job the moment it hits your Account. Adjust allocations when income changes so your plan always reflects reality, and you always know what is safe to spend.
Accounts & Transfers
Create checking, savings, credit, and other Accounts. Transfers keep everything balanced across Accounts and Envelopes—automatically.
Templates for recurring Transactions
Build Transaction Templates for recurring income and bills, then apply them with a single click — a paycheck split across a dozen Envelopes becomes one action instead of a dozen entries.
Easy Transaction import
Import from your bank in CSV, OFX/QFX, or QIF. Intelligent Import skips duplicates, suggests Envelopes using patterns learned from your own Transaction history, and re-imports new downloads hands-free with an optional folder watch. Every match is made on your own computer; nothing is uploaded for processing.
Reconcile with confidence
Use the Reconcile view to match statements quickly while seeing only uncleared activity, so a monthly statement is cleared in a single pass.
Reports you can carry
Print Envelope summaries in multiple sizes—from business card to letter—for quick reference anywhere.
Available in six languages
Use Principal Plan in English, German, Spanish, French, Italian, or Portuguese — switch languages anytime in Settings.
Detailed documentation
Access the Principal Plan Help Library for a multi-language guide to using Principal Plan.
Get Principal Plan
60-Day Free Trial. No credit card required and no account to create—just install it, set it up, and try it out for 60 days. After the trial, purchase your preferred license in the app: monthly, annual, or a one-time forever license.
Principal Plan itself runs on Windows and Mac — open this page on your computer to install the free trial. Principal Plan Mobile pairs with it to keep your Envelope balances with you. It is available for Android on Google Play and iPhone and iPad on the App Store.
Choose your platform to get started.
What makes Principal Plan different?
- Not a web app — Desktop‑native software that runs locally on your PC or Mac. Your data stays on your computer, and nothing is shared unless you choose to pair a mobile device — and then only in a form we cannot read.
- Envelope budgeting — Unlike traditional budgeting that tracks spending after the fact, Principal Plan works by allocating income across Envelopes the moment it arrives. You plan with what you actually have in hand, not future projections or estimates.
- Professional‑grade ledgers — Access Account and Envelope ledgers that give you precise control over every Transaction. A dedicated Reconcile mode makes matching bank statements fast and painless while showing only uncleared activity.
- Accounts stay perfectly balanced — By design, the total of all your bank Accounts always equals the total of all your Envelopes. This mathematical certainty eliminates the confusion and discrepancies common in other financial software.
- Clear "available to spend" — Every Envelope shows exactly how much money is available for that category right now. Visual warnings appear when you go below your threshold, making overspending immediately visible and fixable before it becomes a problem.
- Templates & Allocation Plans — Transform recurring income and bills into reusable Templates. Apply your entire paycheck allocation or monthly bill payments with a single click, automatically distributing money across the right Envelopes.
- Flexible organization system — Bundle Envelopes together to group related categories. For instance, housing could bundle together mortgage, utilities, and more.
- Portable reference materials — Print wallet-sized balance summaries in multiple formats (business card size, planner size, or full letter) so you can carry your current Envelope balances with you for quick reference while shopping.
Simple, Fair Pricing
After your 60-day trial, purchase your preferred license in the app:
- Monthly $1.99/month
- Annual $19.99/year
- Forever $39.99/once - use it forever with no recurring fees
Prices are in US dollars. Prices in other currencies are set by the Microsoft Store or the Apple App Store. For questions, please contact us at info@thomsens.net.
Frequently Asked Questions
Is this a web app?
No. Principal Plan runs locally on your own PC or Mac. Your data stays on your computer and there is no cloud account. If you choose to pair a mobile device, your data is cached on our servers so your phone can retrieve it, encrypted end-to-end before it leaves your desktop. The encryption keys are derived from a 256-bit random key your paired devices exchange directly and a passphrase you choose; neither is ever sent to us, so we cannot read what we store.
How does pricing work?
Use Principal Plan free for 60 days. After the trial, purchase your preferred license in the app: $1.99/month, $19.99/year, or a one-time forever license for $39.99. The forever license lets you use the software indefinitely with no recurring fees.
What is Envelope budgeting?
Envelope budgeting gives every dollar a specific purpose the moment it arrives — you allocate income across virtual Envelopes for each spending category. Unlike traditional budgets that track spending after the fact, it helps you plan with what you actually have available.
What platforms are supported?
Principal Plan runs on Windows 10 or later and macOS 12 (Monterey) or later. Try it free for 60 days with no credit card required.
Can I import Transactions from my bank?
Yes. Principal Plan imports the CSV, OFX/QFX, and QIF files that banks provide. Intelligent Import detects duplicates, suggests Envelopes using patterns learned from your own Transaction history, and can optionally watch a folder for new downloads. All matching happens locally on your computer.