Assalamualaikum.I work in a company.there I have to write some documents which are not true.I can't avoid it.does it invalidate my fast??I try not to write but some things need to write.what should I do???please help me.I am really concern about it.does writting this kind of false dacument invalidate fast???

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

The documents you write do not affect the validity of your fast and does not make it invalid. However, it does reduce your reward as narrated by Abu Hurayrah who stated that the Prophet said: “Whoever does not give up forged speech and evil actions, Allah is not in need of his leaving his food and drink.” [Al-Bukhari]

Therefore, you are not required to make up for the days you had fasted while writing these documents. However, you should repent to Allah and refrain from such false documents.

Allah knows best.