Unfortunately: the Do Not Call Registry does NOT include businesses. Only individuals can be put on this list: Do Not Call Registry - Not for Businesses
However - you might want to try the following when these telemarketers call:
1. Ask the telemarketer: What's your business' name? Where are you located? (jot it down).
2. Are you a licensed tax professional? E.A., C.P.A. or Attorney?
(they will probably say:" no , but we have them on staff ").
3. You will say: No? Then what you are doing is ILLEGAL according to Publication 470 of the IRS. Publication 470
Publication 470 - states that non-professionals can not make "uninvited solicitations of employment."
4. If you call again - I will report your company to the IRS - Office of Professional Responsibility - OPR.
P.S. if you are my client or even NOT a client - and you want to file a complaint to the OPR. I know the attorney to send the complaint to. Contact me at 866 525 7302 and I will help you with this process.
I have written extensively on my blog about the practice of cold calling tax liens. While there are some good companies that use this form of marketing (2020 Financial in Colorado comes to mind) - many others do NOT run a good shop.
Here's our previous articles on the tax lien telemarketing phenomena: