Allah the Almighty declares:

اِنَّ الصَّلٰوۃَ کَانَتۡ عَلَی الۡمُؤۡمِنِیۡنَ کِتٰبًا مَّوۡقُوۡتًا

“[…] verily Prayer is enjoined on the believers to be performed at fixed hours.” (Surah an-Nisa, Ch.4: V.104)

Salat must be strictly offered within the appointed times set. Anyone who misses Salat within its appointed times and without reason – out of laziness or weakness – cannot make it up and should constantly seek forgiveness from Allah the Almighty as this is a major sin.

Those who unintentionally miss Salat due to forgetting or being asleep (without the intention of missing Salat) can offer Salat immediately after they remember or wake up.

In Sahih Bukhari, the Holy Prophet^(sa) is recorded to have said:

مَنْ نَسِيَ صَلاَةً فَلْيُصَلِّ إِذَا ذَكَرَهَا، لاَ كَفَّارَةَ لَهَا إِلاَّ ذَلِكَ

“If anyone forgets a prayer they should pray that prayer when they remember it. There is no expiation except to pray the same.” (Sahih Bukhari, Book Times of Salat [Prayers])

Someone wrote to Hazrat Khalifatul Masih V^(aba) and asked, “Is it true that if someone misses a single prayer, their prayers of the last 40 years are wasted?”

Huzoor^(aba), in a letter dated 20 February 2020, gave the following reply:

“[…] The answer to your question about Salat is that if a prayer is missed due to forgetting, then the Holy Prophet^(sa) has said that it should be offered as soon as one remembers the missed prayer. This is the expiation for forgetting to offer a prayer. However, it is a grave sin to intentionally skip a prayer. Its forgiveness can only come from repentance [taubah], seeking forgiveness [istighfar] and a firm resolve and promise not to repeat such a mistake in the future.” (Al Hakam, 27 August 2021)