New biz client. Tax return reports cash basis but they've actually been using the accrual basis. If I do a 3115 it will have zero effect. Hoping someone will tell me to just change the checkbox to accrual and move on. Opinions?

In 9 days have been referred to three new business clients as their accountant is retiring (3 different accountants). One got a new girlfriend and wants to spend her money, two is ill and three just wants out.  Weird coincidence in a little over a week.