A modular filling device for filling at least a first reservoir (111) of an applicator (100) with a fluid is proposed. The filling device comprises a container holder (310) with a holding area (320) on which a container (330) is held. The applicator is mounted along a securing direction on an applicator holder (200). In order to permit the greatest possible flexibility in the choice of the container, the container holder (310) can be connected to the applicator holder (200) along a connecting direction that runs transversely with respect to the securing direction for the applicator.
