Most serious freelancers will have accountants who provide (very crude) software portals which handle the company revenue stream tied to the business bank account. This allows each transaction to be reckoned against ongoing projects, raise invoices, handle documentation etc which are all present in that portal.

Admittedly, these tend to be quite crude but I have the added comfort that my accountant can get involved when necessary as they are familiar with it.

So perhaps the target market should be a different kind of freelancer.