Unsubscribing a Business from Direct Mail?

There are numerous ways for people to opt out of receiving credit card offers, direct mail, etc. After doing this a while back, there was a big reduction in junk mail.

However, now I am getting a lot of credit card offers for my business (LLC). I looked around the internet and can't find an easy way to opt out a business from credit card offers, etc. When I call the opt out number they want me to type in a SSN, but the business is identified by EIN or something else.

Any advice on how to opt out a business from junk mail and credit card offers?