Going independent is a huge choice. Not only do you have client risk, income risk etc, but one of the big underappreciated challenges is simply getting paid. Once you are truly running your own business, cash flow on a consistent basis is absolutely critical, which is why you need to have flexible and reliable billing software which can help you collect fees in a compliant way.
FINSUM: You need to have your tech stack solid as rock when going independent and collecting payment in a compliant way is beyond critical. Make sure to investigate the options!