why mail? if you do the address would be in the TT filing instructions. since you didn't specify what state it's impossible to give you a mailing address should the filing instructions not have it. just about every state allows payment through its website. ach bank payments are free, there may be fees for credit or debit card payments. you usually can also specify the date the payment is to be made. at the end, you can print a document that has info should there ever be a question like document number, date of payment, amount, and funding source. this info varies by state.
