01
Dashboard with company switcher
Revenue and invoice-status stats from the invoicing service. Switching company changes the active tenant for every API at once.
Case study · 07 / 09
VKS
Online invoicing & accounting SaaS
Invoicing and online accounting for small businesses and accounting offices — many companies on one account, every Polish VAT rule handled, data filled in straight from the GUS registry.
Partner
VKS
Industry
Fintech · Accounting
Platform
Web app (PWA) + microservices
Our role
Frontend & invoicing service
The product
What it does
One login, several companies. Users issue sales, pro forma, draft and correcting invoices, manage contractors and bank accounts, and buy licences and add-on packages on subscription — with exchange rates taken from the National Bank of Poland.
Our part
What we built
A Vue 2 + TypeScript PWA talking to three independent microservices — auth, licences and invoices — and the Laravel invoicing service behind it, signed with RS256 JWTs and rendering PDFs with DomPDF.
Under the hood
The hard parts
- 01
Multi-tenant across three APIs
Separate axios instances and base classes per service, with the active company sent to every API in an X-company header.
- 02
Totals calculated by the server
Every change of quantity, price, discount or VAT rate is recalculated by the invoicing service — net and gross strategies, discounts and rounding to the grosz.
- 03
Every VAT case covered
Previews grouped by seven VAT rates (23/8/5/0%, exempt, n/a, n/a EU), amounts written out in Polish words, and corrections showing before, after and the difference.
- 04
Less typing, fewer errors
Contractor data pulled from the GUS REGON registry by tax number, declarative validation with Polish messages and numbering series that reset every month.
The outcome
Small businesses and accountants issue correct Polish invoices for many companies from one place.
Inside the product
6 screens, explained
Demo data · click any screen to enlarge
02
Issuing an invoice
A live line-item table: each change of quantity, price, discount or VAT asks the server calculator for VAT, net and gross. The contractor’s default 5% discount fills in by itself.
03
Invoice preview
Totals broken down by every VAT rate — including exempt and EU reverse charge — and the amount written out in Polish words.
04
Invoice list
Server-side filtering, sorting and paging: date range, document type, minimum amount and payment status (paid, partly paid, unpaid).
05
Subscription configurator
Step one of four: licence, billing period with a length discount and add-on packages, priced live in the basket before invoice details and online payment.
06
Contractor from GUS
Type the tax number, click “Fetch from GUS” and name and address fill in from the REGON registry. Validation errors speak Polish.
Stack
Frontend
- Vue 2
- TypeScript
- Vuetify
- Vuex
- vee-validate
- vue-i18n (PL/EN)
- PWA
Invoicing service
- Laravel 9 / PHP 8.1
- JWT RS256
- DomPDF
- NBP exchange rates
Quality
- Jest
- Cypress
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