PHP · Vite · jQuery
InvoiceMaker SaaS
Self-serve invoice builder with PDF export, recurring billing and a public REST API used by 4k+ freelancers.
- Industry
- B2B SaaS for freelancers
- Duration
- Ongoing product
- My role
- Founding engineer
- Client
- InvoiceMaker (own SaaS product)
Challenge
Freelancers in the EU need invoices that respect 12 different VAT regimes, reverse-charge rules, multi-currency, and a public REST API for integration with their own tools — without learning accounting software.
Solution
Self-serve invoice builder with PDF export (DomPDF + custom templates), recurring billing via Stripe Cashier, country-specific VAT logic abstracted into a rules engine, and a public REST API documented with Swagger so power users can automate.
Technology stack
PHP 8.2ViteAlpine.jsMySQLDomPDFCashier (Stripe)
Result
4k+ active users across 12 EU countries, near-zero support load thanks to inline validation, and a public API now powers integrations into Notion, Make and Zapier.
Key metrics
- 4k+
- active users
- $0
- support tickets/week
- 12
- EU VAT regimes
“
Finally an invoice tool that gets EU VAT and reverse-charge right. The public API let me automate everything from Notion.
Lukas B.— Freelance developer, customer
