Using a different address to apply, or changing the billing address of an account after it is established, can create confusing information in the account holders' credit reports. For example, for a number of years I had one of my personal credit cards billed to my office address. This causes my credit report to show that I "lived" at the office address for a period of time.

I really don't understand why you would use your billing address for other people's accounts. Most card issuers offer paperless billing. Use the correct billing address for every account, turn off paper statements, and manage the accounts online.