Just wanted to correct that a TIN or EIN is a "Federal" deal, one that you get from the IRS. If you ever want to have employees, you fill out Form SS-4 and obtain an EIN. Also, if you ever find yourself as the Executor of an Estate (
which I've done 3 times thus far) you'll need an EIN to file taxes.
If you are a sole-proprietorship or a partnership (
owner operated business) then you'd fill out Form SS-5 for a TIN (
basically a Social Security Card). Again, if you are a sole-proprietor you can *and will* most likely use ONLY your social security number as the way you file your taxes.
Generally there is no correlation with your local city/county/municipality requiring you to have a business license and/or a TIN/EIN before obtaining one or the other.
However, some cities (like LA for instance) tie in your business license with their ability to TAX YOUR BUSINESS and want to have one of the three above numbers on file when issuing your business license. (
Just so that they can jack you up come next year after you file your income statement, as your license fee is directly related to your income. The more you make, the more they take!.)

Just give them your SS# when filing for your business license.
In any event, you do not need a business license to file a Form SS-4 or SS-5. Go to the IRS site and click.... you'll find out fairly quickly that they'll let you file that form. In fact, you can file as many different ones as you like!

(
For what I don't know.... but you can surely do it till your eyes turn red.)
From the IRS:
This EIN is your permanent number and can be used immediately for most of your business needs, including:
•Opening a bank account
•Applying for business licenses
•Filing a tax return by mail
However, it will take up to two weeks before your EIN becomes part of the IRS's permanent records. You must wait until this occurs before you can:
•File an electronic return
•Make an electronic payment
•Pass an IRS Taxpayer Identification Number (TIN) matching program
How Do I Get A TIN?
SSN
You will need to complete Form SS-5, Application for a Social Security Card (PDF). You also must submit evidence of your identity, age, and U.S. citizenship or lawful alien status. For more information please see the Social Security web site.
Form SS-5 is also available by calling 1-800-772-1213 or visiting your local Social Security office. These services are free.
EIN
An Employer Identification Number (EIN) is also known as a federal tax identification number, and is used to identify a business entity. It is also used by estates and trusts which have income which is required to be reported on Form 1041, U.S. Income Tax Return for Estates and Trusts (PDF). Refer to Employer ID Numbers for more information.
Obtaining a "Registered Agent" is ONLY needed if you are filing for, and want to be, an official Corporation or LLC. In fact, you can be your own Registered Agent if you have a physical address (not a PO Box). Basically the "agent" is a person that is always there to accept any legal and/or tax documents that may come your way. Which means.... if the IRS decides to audit you, or raid you, then they contact your "agent" and don't show up at your place while you're talking with customers. Some local agencies (including cities etc.) like to see an official agent on file lest they get nervous should there ever be a condition where they want someone official to serve papers on. That does not however release you from the wrong end of the swinging stick when it swings your way!
Having an agent is only if you want to file as an Corp/ LLC. Plus if say you ever move your address, the address of the "agent" stays the same. OTOH; My family always owned businesses (from the 40's till 90's), and I've owned business most of my life and never had a "registered agent".