re: Besides W2 employees, what percent of people are 100% honest with taxes?

Our tax account claims 100% of all our income sources but pushes the limits on deductions, credits, etc. He always says that is the key to minimize problems while limiting taxable income. I do know several people (including some family members) that DON'T claim all income, especially goods and services in a barter system while also pushing the limits on expenses and deductions for small businesses and self employed. I think this is pretty common with non-W2 wage earners.