Sometimes when a poor person asks me for money, he shows me a document that testifies to his being a genuinely needy person. What am I supposed to look for on these documents?
The first things you would want to do is to read it over, and make sure that the date is valid, and it was indeed given to this person.
If the amount of money you want to give him is significant, you can also verify the document’s authenticity by calling the phone number of the Rov or organization that is testifying for this person. This is awkward, but if it is a significant amount, you can tell him that you will take down the numbers, and that he should get back to you in a day or two.
It is important to also remember that although you do want to verify the authenticity of the person collecting the money, remember that we are dealing here with a human being. If, indeed he is a poor person, checking the paper etc., is embarrassing for him. Therefore, according to the circumstances, act with caution but with care. You might want to apologize, because since there are unfortunately such people you are forced to look at the document etc. Show him that you care about his feelings, even though you are scrutinizing him and his claim.
May Hashem help us so that our tzedakah go to the right sources.