Passion
Arguably the most important thing you need in order to start a freelancing business is passion. Specifically, you need passion for something that can be converted into a freelancing business. That passion can be for writing, photography, programming or just about anything else that you can turn into a service to sell to other people, but unless you have something that you are really passionate about, you are not going to be able to do very well in the freelancing business you start. There are going to be depressing times and lulls in freelancing contracts and in order to weather those times, you really need to enjoy what you are doing.

Permanent Internet Connection
This would be the point to argue with passion about the most important thing you need in order to start a freelancing business. A permanent internet connection is important because freelancers that become successful are at their computer several hours a day. This does not mean you have to chain yourself to a computer, but you do need to treat a freelancing business like a job and for that reason pick a significant chunk out of your day and use that chunk at your computer freelancing. In order to secure contracts, do work and send finished projects to clients however, you do really need to have a permanent internet connection. It facilitates easy communication in a way that would not be possible otherwise.

An Online Payment Account
This is really more important in online freelancing (i.e. writing, or photography) than it would be in offline freelancing (i.e. consultancy work), but in general it is a good idea. Many people don’t like online payment services because of the high fees that they charge on every single transaction and while there is certainly some truth to this argument, at the same time online account will help you out a great deal in getting payments completed both through sending and receiving them within a reasonably quick amount of time.

Time
Another thing that you need in order to start a freelancing business is time. Just like any other business, a freelancing business will be slow at first. You have no reputation and can not really expect most people to give you a chance right off the bat. Typical freelancers enter with little work and lower wages and over time are able to command more demand and higher wages for the work that they do. At the start however, your time spent finding new work will be much larger than it will be later on and that is why you need some extra time to devote to the operation when you first start your freelancing business. Without it, chances are pretty good that your business will not go anywhere except into the ground.