This document outlines the tax calendar and payment requirements under the Profession Tax Act 1975 for two types of taxpayers: 1) Profession Tax Enrollment Certificate (PTEC) holders must pay tax by the 30th of June or within one month of enrollment/revision. E-payment is available. 2) Profession Tax Registration Certificate (PTRC) holders must pay tax in chalan MTR-6 and submit online returns in Form IIIB by the 10th of April/month. They must enroll for e-services first. Tax is due monthly if liability is over Rs. 50,000 or annually if under Rs. 50,000. E-payment and returns are now mandatory.