Q: If I have wrongly claimed Gift Aid, what is required of me now by sharia in this case?
The transaction is now complete so is not reversible and was processed via a friend. If the charity does end up claiming gift aid, should I pay some money to the government to balance things out?
What can I do Islamically to rectify the problem – Is repentance to Allah sufficient?
الجواب حامدا ومصليا ومسلما ومنه الصدق والصواب
You should seek repentance yourself and also advise your friend and the charity concerned that if they have misrepresented the facts to claim Gift Aid then this is a sin and they should return any money that has fraudulently been claimed.
As the matter relates to the rights of the creation, simply seeking repentance from Allah swt will not suffice. The matter is all the more grave as it relates to the public purse which is the property of everyone as opposed to the property of a single individual or a limited number of individuals. Therefore, it becomes practically impossible to seek forgiveness from the wronged parties.