Money & WorkHow it works
How to avoid going broke at year-end as a freelancer.
What lands in your account isn't yours. VAT merely passes through you; after business costs, what's left is profit. From that come income tax, health and pension contributions, often leaving only half. From your first invoice, move a fixed percentage to a separate account and don't touch it until the tax office comes calling.
Useful: Work your hourly rate backwards: double your desired net, divide by billable hours.
Source: de.wikipedia.org