If you are paying your quarterly taxes in the U.S.A., then you will have a payment due this month. Why should you bother calculating and paying your quarterly tax payment? Well, do you want to be in business this time next year? Remember, quarterly payments are an estimate of what you think you will owe in income taxes for the Feds and your state. This number is based on profits only, so be sure to deduct any operating expenses like show fees and supplies.