That W number is almost certainly your MD tax ID. You can call MD SDAT to confirm.
Licensed in Maryland. Information here is general, does not create a lawyer-client relationship, nor is it a substitute for consulting with an experienced attorney on the specifics of your situation.
You only have one tax ID #, and it is the federal EIN. Use that one on your Maryland return, same as federal. Maryland issues an SDAT entity ID number for your Maryland-organized business, but it is not a tax ID #.
The "W" number is likely your State Department of Assessment and Taxation (SDAT) ID number. It's not technically a "State Tax ID number," it's more of a tracking number for the State when processing your business personal property tax forms.
SDAT uses "W" for domestic (based in Maryland) LLCs.
You can always call SDAT at 1-888-246-5941 to confirm your SDAT ID number is correct.
Licensed in MD, PA and DC. This is not legal advice. I am not your attorney. You should consult with an attorney licensed to practice in your jurisdiction regarding your specific circumstances.
There is also a central registration number that you may need if you are going to file a sales and use tax return or an employer withholding return. You can learn more about this number on the comptroller's web site at www.marylandtaxes.com. There is an application form you can complete to obtain this number. The "W" number you have is used for income tax return purposes and generally is assigned at SDAT's acceptance of your articles of organization.
Responses and postings herein are not intended as legal advice and are not intended to establish an attorney-client relationship. I am only retained as your attorney through the execution of a written services agreement between you and I. You should consult with an attorney admitted to practice in your state before taking any legal action.