A company that places products of concern on the Estonian market must keep records of them. Data must be submitted to PROTO by 31 January each year as part of the reporting process, or to the PRO for transmission to the register (specific dates are agreed upon between the parties in the contract). Records must be maintained continuously, not just before the reporting deadline. This ensures a lower administrative burden during the reporting period, as it can be difficult later on to determine which products were products of concern, in what quantities they were placed on the Estonian market, and whether the responsibility remained with the company, the supplier, or another party. If the company fulfills its obligations through a PRO, the necessary data must be submitted to the PRO in the agreed format and by the specified deadline.