Virginia's support guidelines are only as accurate as the income figures fed into them. When one parent works for cash or quits a good job right before a hearing, the guideline result stops being fair.
Courts can impute income based on earning capacity, considering work history, education and available jobs in the area.
Proving it takes documentation: bank records, tax returns, social media, lifestyle evidence and sometimes a vocational expert.
Keep records and be specific. 'He makes more than he says' isn't evidence. Deposit patterns are.