All of the online tax stuff is done through a website called ELSTER.
This took maybe a week to do, because I needed to get some security registration information by mail, and use this to go online and generate a security key file that I could upload when logging in. I couldn’t figure it out from the CD, but I eventually realized I could register to pay taxes as a freelancer online as well (no CD needed).
They gave me a software CD to put in my computer. They told me I couldn’t pay taxes as a freelancer on a paper form I must do it online. So at this point I went back to my local finanzamt to request the correct tax payment forms for a freelancer.
Thus far, this is the registration process that gets you in the system allows you to pay your taxes. Maybe a week later I received some papers in the mail with a common tax number for my wife and I, and separate tax ID numbers for each of us. Note that I already had my German tax ID number, which I received as part of the process of getting a residence card. They gave me the right forms, I filled those out, and returned them a few days later. I searched online for which finanzamt served the small town I was in, went in without an appointment, took a waiting number, and when called I told the person, “I must register as a freiberufler, please.” I wrote down that sentence in German on a piece of paper and read it out loud. This is like a local branch of the German tax authority. I first registered at my finanzamt in person. (Note for Americans: see this link about exemption for US/IRS taxes) I’ll preface all of this by saying I have no idea if this is the “correct” way of doing this, but it has worked for my wife and I for several years with no problems. Though we file online together, we fill out different forms. Stpfl – you have these for life) for each of us. So my wife and I have the same tax number (Steuernummer – this identifies the state in which you’re living and hence the finanzamt you’re assigned to if you move to a different state you get a different number), but different tax ID numbers (Idnr. I believe you can file your taxes separately if you want, but my wife and I file together. My wife is an employee of a company (not mine), so I will also cover how she files her taxes. I have my own small business, or in other words, I’m a freelancer. This process is regarding filing taxes in Germany as a freelancer (known as a “freiberufler” in German), and filing taxes as an employee of a company.