BillingEngine vs Puzzle: Which Is Better in 2026?

BillingEngine is an invoicing and light bookkeeping application for freelancers, tradespeople and small businesses in Germany. It was built around one idea: sending a correct invoice should take a few clicks, and the data behind it should be useful afterwards.
Every invoice you create is an e-invoice under the European standard EN 16931, so you meet the German e-invoicing requirements without extra tools or conversion steps. You can create and send invoices and track their status. If a customer pays late, overdue invoices are collected in one list, and you can write a payment reminder that shows the amount still outstanding. The delivery status shows whether it arrived. Quotes can carry an expiry date, are written in your customer’s language and currency, and become an invoice once they are accepted. For regular work, recurring invoices are prepared on the due day, so you only check and release them.
Incoming documents are handled just as simply. Every account gets its own inbox for receiving e-invoices, which is free on every plan and has no volume limit. Paper and PDF receipts can be uploaded or forwarded by email. AI reads the amount, date, tax rate and supplier and assigns them to an expense. Warnings point out mismatches, so you can correct them before they cause problems. Assets can be depreciated by choosing a category, useful life and method, and the schedule is written for you.
Customer data is entered once, including address, tax number, language and currency, and every invoice for that customer reuses it. Time and costs can be collected on projects, and an invoice picks them up with one click. Revenue, expenses, profit and VAT are shown by month, quarter or year, and every figure can be exported.
For your tax advisor, BillingEngine exports invoices, expenses and payments as a finished DATEV booking batch. Bank statements can be imported in CAMT.053 format and matched with payments. Developers get a REST API with an OpenAPI description, and there is an MCP server that lets AI assistants work with your invoicing data.
BillingEngine is focused on the German market and is not a full double-entry accounting suite. Filing advance VAT returns through ELSTER is in preparation, and the figures for the return are already available in the application. A free e-invoice validator and viewer let you check and read e-invoices without an account.

What problem it solves

Since 2025, German businesses must be able to receive e-invoices, and sending them becomes mandatory step by step. Many small businesses still write invoices in Word or Excel, which don’t produce a valid e-invoice, and full accounting suites are often more than they need. BillingEngine lets them create compliant e-invoices (EN 16931) in a few clicks and receive them in their own inbox for free. It also removes the manual work around invoicing: receipts are read by AI, reminders and recurring invoices are prepared for them, and a finished DATEV export goes to the tax advisor.

Alternatives & competitors

sevDesk, Lexware Office (formerly lexoffice), easybill, Billomat, FastBill and Zoho Invoice. Compared with them, BillingEngine is lighter and focused on e-invoicing and simple bookkeeping for small businesses, with a free e-invoice inbox on every plan. The larger tools offer more integrations and a broader accounting scope.

Puzzle is AI-powered accounting software built from the ground up for automation — "the accounting core where agents work for you." Instead of layering AI onto legacy tools, Puzzle built its own general ledger designed for AI agents, so books stay accurate and up to date in real time rather than waiting for a manual month-end close.

What is Puzzle?

Puzzle is a cloud accounting platform where AI agents handle the grunt work — categorizing transactions, reconciling accounts and flagging exceptions — automatically, up to 98% of it, without you writing rules. It keeps financials current day to day, calculates burn rate and runway in real time, and combines the software with optional vetted accounting services for teams that want expert help.

Who it's for

Puzzle serves startups that want daily financial visibility without painful closes, small businesses that need accurate books without building a finance team, and accounting firms and bookkeepers managing many clients. It's especially suited to companies already using modern fintech tools like Stripe, Brex, Mercury and Ramp.

Key features

• AI agents for automatic categorization, reconciliation and exception detection
• Up to 98% automated transaction processing, no manual rules
• Real-time financials instead of month-end snapshots
• Accrual automation for prepaid expenses and fixed assets
• Revenue recognition (cash and accrual)
• Invoicing with send, track and reconcile
• Real-time burn rate and runway calculations
• Native integrations with Stripe, Mercury, Ramp, Brex, Gusto, Rippling and Deel

Books that are always current

Puzzle's biggest shift is timing. Traditional accounting gives you a picture weeks after the fact, once someone closes the month; Puzzle keeps the books continuously reconciled so your financials — including burn and runway — are accurate in real time. For a startup watching its cash, seeing today's true position instead of last month's is a genuine operational advantage.

Automation you can trust

AI in accounting only works if it's controllable, so Puzzle uses a "Governed Automation" model: the AI prepares the work, but humans approve before anything is posted. Every automated action is fully auditable, and the platform is SOC 2 compliant with encryption and role-based access. That balance — heavy automation with human oversight and a clean audit trail — is what makes it safe for real financials.

Built for AI, not retrofitted

Puzzle's key differentiator is its foundation. Rather than bolting automation onto an existing system like QuickBooks, it built its own general-ledger infrastructure specifically for AI agents. That native design is what enables faster closes and continuous, real-time financials — things that are hard to achieve when automation is an add-on to decades-old accounting software.

Connected to your money stack

Puzzle plugs directly into the tools modern companies already run their money through — Stripe, Mercury, Ramp, Brex, Gusto, Rippling, Deel and more — so transactions flow in automatically and stay reconciled. It also supports importing historical data from QuickBooks, making the switch from a legacy system straightforward rather than a from-scratch migration.

Software plus expert help

Puzzle isn't only software — its "Puzzle 2.0" combines the platform with optional vetted accounting services, so a company can run the books itself with AI doing most of the work, or bring in expert bookkeepers and accountants when it wants a professional in the loop. That flexibility lets a startup start lean and add human expertise as it grows, without switching systems or re-migrating its financial history.

Why choose Puzzle

For startups, small businesses and bookkeepers who want accurate, real-time books without the manual grind, Puzzle is a modern, AI-native choice. Its highly automated ledger, governed human oversight, real-time burn and runway, and native fintech integrations make it a practical way to keep finances current and trustworthy — and to spend far less time on the accounting itself.