If someone invalidates a fast of the month of Ramadan by eating, drinking, having sexual intercourse, masturbating, or remaining in the state of janābah until the time of ṣubḥ prayers, in the event that he did one of these things intentionally and voluntarily – and he was not compelled or forced to – then, as well as qaḍāʾ, kaffārah also becomes obligatory for him [i.e. he must keep a fast after the month of Ramadan and give recompense as well].
As for someone who invalidates a fast by means other than those mentioned, the recommended precaution is that in addition to qaḍāʾ, he should also give kaffārah.