My question is on internal do not call. If we call a customer who has an account with us and they request to be removed from calling we place that account on our internal DNC list. However, we have several customers with multiple accounts. If we called them and they make the request must we apply to every account that customer has or just the account we called them about?

It is customer and not account:

A company with which a consumer has an established business relationship may call for up to 18 months after the consumer’s last purchase or last delivery, or last payment, unless the consumer asks the company not to call again. In that case, the company must honor the request not to call. If the company calls again, it may be subject to a fine of up to $40,654.