The RTS state that the fraud rate for use in the TRA exemption should be calculated on a “rolling quarterly basis (90 days)”. It is not clear if this means that the fraud rate should be recalculated every day using the trailing 90 days of data, or should be recalculated once every 90 days (using the trailing 90 days of data).
Article 19(1) of the Commission Delegated Regulation (EU) 2018/389 refers to a calculation on a “rolling quarterly basis (90 days)”. Article 20(2) of the Delegated Regulation states that payment service providers should cease applying the exemption if the “monitored fraud rate exceeds for two consecutive quarters the reference fraud rate applicable for that payment instrument or type of payment transaction in that exemption threshold range”. Accordingly, Articles 19(1) and 20(2) of the Delegated Regulation should be read together in a systematic way, such that the calculation on a rolling quarterly basis (90 days) should be interpreted as a calculation once every calendar quarter.