In accordance with Article 6 of Regulation (EC) No 396/2005, Belgium, hereafter referred to as the evaluating Member State (EMS), compiled an application to modify the existing MRL for the active substance prosulfocarb in fennel. In order to accommodate the intended use of prosulfocarb, the EMS proposed to raise the existing MRL from the limit of quantification 0.05 mg/kg to proposed MRL 1.5 mg/kg. The EMS drafted an evaluation report in accordance with Article 8 of Regulation (EC) No 396/2005, which was submitted to the European Commission and forwarded to EFSA on 24 May 2012. According to EFSA the data are not sufficient to recommend a MRL for fennel since the metabolism of prosulfocarb in primary crops is not adequately addressed. In addition, a data gap regarding studies investigating the nature of residues in processed crops was identified. EFSA therefore does not propose to amend the MRL for prosulfocarb in fennel.