Do some employers here really require proof of residency? Our tenant is saying that her son needs one so she's?

Do some employers here really require proof of residency? Our tenant is saying that her son needs one so she's asking my mother to provide her photocopy of her ID and a signed letter proving that they are indeed residing in our place. I'm thinking that a Residence Certificate from barangay would be enough. I'm only afraid they might use it for something else. Thanks for anyone who could help..