Going solo?
You have a personal juris number. It’s perfectly fine. I mean, it works. You can file appearances, sign pleadings, and appear in court. It does all of the things you need it to do. 
One of the rules of building your own practice is to build for success. If something is worth doing it is worth doing right – from day 1.
Here are 3 reasons you need a law firm juris number:
Where you start is not where you’re going to end up. You’re going to do this right. You’re going to grow.
1. Bank accounts – setting up bank accounts sucks. It takes time. Many banks have a limited grasp of how to set up an IOLTA account. When you associate your bank accounts with your personal juris you are asking to have to open new accounts, get new checks, and go through bankland again when and if you add someone to your firm.
2. Coverage – of counsel relationships are nice. If you have a conflict or are sick a lawyer who is “of counsel” to your firm can appear on your behalf. In an appearance under your individual juris number that’s not the case. That lawyer would have to file an appearance in addition to yours. Forcing all sorts of obligations onto that lawyer such as a fee agreement and possibly a motion to withdraw.
3. Growth – someday you may want or need to add an associate or a partner. If you don’t have a firm juris number you’ll be forced to get one at that point. And then you’ll have to do all new appearances in your file. What a waste of time.
Get it right from the start. Even if you’re solo – get a firm juris number.