The debtor has to pay the lawyer's costs and expenses

If a commercial debtor defaults on payment  the creditor of a payment claim also has a statutory claim to reimbursement of statutory fees pursuant to the German Lawyers' Compensation Act (Rechtsanwaltsverguetungsgesetz).   

The attorney fees are legally fixed according to the law on remuneration of lawyers and depend on the value of the dispute.  Fees are not a percentage of the debt, but they are fixed in a fee scale.

The respective claim will also be presented in the collection letter.