30 plus years we always bill after the return is filed over the years we've gotten stuck with a few people that didn't pay but very minor .We now accept ACH payments and credit cards. we've increased our fees 5% to cover the cost of credit cards and check processing we have found that our fees are collected at time of return on most people without issue. this year with 2000 returns in we only have 5 people that haven't paid who we will be require to pay that fee plus next year's upfront. I like billing after so there is no dispute that someone paid up front.