Money & WorkFact
The most expensive loan is the one you never applied for.
An overdraft is a pre-approved facility on your current account. You sign nothing; the balance simply goes negative. Convenient, but the interest is usually far higher than on an instalment loan, often above 10% per year. Sitting €1,000 in the red permanently costs you over €100 a year purely for convenience.
Useful: If you're overdrawn for more than a few weeks, refinance into a cheaper instalment loan.
Source: de.wikipedia.org