اللَّهُمَّ تَقَبَّلْ صِيَامِي وَقِيَامِي وَرُكُوعِي وَسُجُودِي
Allahumma taqabbal siyami wa qiyami wa ruku'i wa sujudi
O Allah, accept my fasting, my standing in prayer, my bowing, and my prostration.
The anxiety of acceptance — will Allah accept my Ramadan? The Salaf used to spend six months after Ramadan asking Allah to accept the worship they did during it. Acceptance is not guaranteed by performance. You can fast perfectly and have it rejected because of a character flaw. This du'a asks for the one thing that matters: that your effort counts, that it registers, that it is not returned to you empty.
Related Du'as
اللَّهُمَّ إِنِّي صَائِمٌ وَعَلَى رِزْقِكَ أَفْطَرْتُ فَتَقَبَّلْ مِنِّي إِنَّكَ أَنتَ السَّمِيعُ الْعَلِيمُ
O Allah, I fasted for You and I break my fast with Your provision. So accept it from me. Indeed, You are the All-Hearing, the All-Knowing.
Hasanذَهَبَ الظَّمَأُ وَابْتَلَّتِ الْعُرُوقُ وَثَبَتَ الْأَجْرُ إِنْ شَاءَ اللَّهُ
The thirst is gone, the veins are moistened, and the reward is confirmed, if Allah wills.
Hasanاللَّهُمَّ أَهِلَّهُ عَلَيْنَا بِالْأَمْنِ وَالْإِيمَانِ وَالسَّلَامَةِ وَالْإِسْلَامِ رَبِّي وَرَبُّكَ اللَّهُ
O Allah, let this moon rise upon us with security, faith, safety, and Islam. My Lord and your Lord is Allah.
Hasanإِنِّي صَائِمٌ إِنِّي صَائِمٌ
I am fasting, I am fasting. (Say this when provoked while fasting.)
Sahih