Matches in the qualifying phase may be played in daylight or under floodlights. If played under floodlights, the illuminance must correspond to the requirements set in the UEFA Stadium Infrastructure Regulations.
From the play-offs onwards, matches must be played under floodlights and the average level of horizontal illuminance must be at least 1,500 Eh (lux) and the uniformity ratios must be U1 > 0.5 and U2 > 0.7. The average level of vertical illuminance must be at least 1,250 Ev (lux) and the uniformity ratios must be U1 > 0.4 and U2 > 0.5. For the play-offs only the average level of horizontal illuminance may be at least 1,400 Eh (lux) and at least 1000 Ev (lux) of vertical illuminance.
Clubs must ensure that floodlighting installations are maintained and provide UEFA with a valid lighting certificate issued within the previous 12 months. UEFA may conduct an independent assessment of lighting levels in stadiums and will notify the clubs in good time of the results of such assessments and of any corrections to be made.