Giving money collected in a charity box to a charity other than that which ownsthe box

I have a collection box for one of the charities, and once it is filled with money I want to give it to a different charity which I believe to be more trustworthy.

Praise be to Allah, and blessings and peace be upon the Messenger of Allah:

We put this question to Shaykh Muhammad ibn Saalih al-‘Uthaymeen, may Allaah preserve him, who responded by asking,

“Why did he agree to keep a box for this charity?”

(We said:) Because it was the charity that he knew of, then he found another that is more trustworthy.

(He said:) It is not permissible. So long as he collected the money with the intention of giving it to the first charity, it is not permissible for him to give it to another.