Invoicing without the hassle, with numbers that always add up
Factisk is a web-based invoicing system for Dutch freelancers and small businesses. Customers, products, invoices and payments in one place, with a PDF that never changes once the invoice is finalised.
Everything for your invoicing
One clear place for customers, invoices and payments
Invoices with a clear status
From draft to final, sent and paid. Overdue invoices are detected automatically from the due date and the outstanding amount.
Numbering without gaps
An invoice only gets a number when it is finalised. Deleting a draft never leaves a gap in your sequence. The format is configurable per company.
VAT and totals calculated by the server
All amounts are calculated server-side with exact decimals and VAT per rate. The editor shows live totals using the same calculation as when saving.
PDFs that stay fixed
A finalised invoice is stored as a PDF and never changes afterwards. Drafts carry a DRAFT watermark. Attachments are added per invoice.
Payments and outstanding balance
Register payments per invoice. Paid and outstanding amounts are always derived from the payments, so your overview is correct.
Works with your AI assistant
Connect Claude or ChatGPT via MCP and let your assistant look up invoices, create drafts or register payments, within the permissions you grant.
How it works
From customer to paid invoice in three steps
Factisk keeps your administration simple. You record customers and products once and reuse them on every invoice.
Record customers and products
Customers with contact persons, products and services with price and VAT rate. Archive whenever you like, no need to delete.
Create a draft and finalise it
Add lines, watch the totals update live, attach files. On finalising, the invoice receives its number and a fixed PDF.
Mark as sent and register the payment
As soon as a payment comes in, record it. Factisk calculates the outstanding amount and marks the invoice as paid.
AI assistant
Ask your assistant which invoices are still open
Factisk has a built-in MCP server. Claude, ChatGPT and other AI assistants connect securely via OAuth 2.1 and only get the permissions you choose, per connection and per company.
Read how the connection worksAvailable tools
Look up customers
Look up products
View invoices
Outstanding invoices
Create a draft invoice
Register a payment
Totals and VAT are always calculated by the server. Write actions are idempotent, so a repeated request never creates a duplicate invoice.
Solid foundation
Built so you can trust your administration
Files only after logging in
PDFs and attachments are never reachable through a public link.
Strictly separated per company
Every query is filtered on the active company. Other people's data does not exist for you.
Audit log of changes
Write actions are recorded with their source: web, AI assistant or system.
Proven technology
Django and PostgreSQL as the source of truth, with a modern Next.js interface in front.
Ready to get your invoices in order?
Log in to your Factisk environment or explore all features first.