Social security court rules ZUS must pay interest from 30 days after certificate submission, not court verdict date.

The Supreme Court reversed the lower court's decision, ordering the Social Insurance Institution (ZUS) to pay interest starting 30 days after the insured submitted medical certificates rather than from the court's verdict date. The insured argued that ZUS failed to verify the authenticity of the certificates during its control procedure, causing an unjustified delay in recognizing the right to sick pay. The court held that because ZUS did not conduct necessary control measures despite having all data, it was in default, and procedural delays in the lawsuit could not excuse this administrative inaction.