“Let’s take an example: Your client is a commercial company. You did the job and issued an invoice with the amount in question due on March 15. It’s March 16 and your client has not paid on time. You are entitled to the debt money, a fixed sum of CZK 1,200 as recovery costs (since the client is a commercial company), and also default interest, which starts accumulating on March 16 and increases over time,” Melkus explains.