I am only in my business 7 months and cannot really put my hand on heart to say i have yet earned any money or much anyway- no accounts either yet to show. Im in property and the turnaround on payment is long and i have spent almost all of my saving setting up this business.
In my experience, if you show a 3 -5 yr business plan, showing project income and income to date, it should demonstrate to a bank the viability of your business, and show that you have thought it through. If you can get a qualified accountant to prepare it or sign it, even better.