Building business credit fast you can either use your good personal financial situation and tie that to your business, or you can take on partners who have a good track record working with the banks. It is also a very good idea to choose a bank where you can establish a personal financial record with them that is positive, so then they are more willing to work with you on the business side. Most importantly you must always pay your bills on time and keep your debt to income ratio low. If you plan on getting credit on your own, at first it may have to come from your personal finances which can put your home at risk, or whatever collateral you are using. But at least you can get money to establish a business relationship with the bank.
The other way is to take on a partner or two and have them be a part of the business. With more people willing to share the risk and put up collateral it is easier for the bank to decide to give you a line of credit. Also the line of credit will be much higher the more collateral you put up. As you go on and the business starts to do well, banks will then be much more willing to extend you credit. Although you may need the money right away, it can take some time to build up your business credit worthiness unless you take on partners. That is a decision you have to seriously think about, but it may also be one that you must make in order to keep the business up and running. Without capital there is no way you can stay in business, right?