The overdraft has a fair interest rate of 11% p.a. on the overdrawn amount. The interest accrued is 100% tax deductible as a business expense if it was incurred for business purposes.
The interest will always be accrued from your Kontist account at the end of a calendar quarter: 31.3., 30.6., 30.9. and 31.12.
There are no further charges.