Filing frequencies and due dates, late filing information, and other resources related to filing your excise tax return. Be sure to include your parcel or account number in the email.Make an electronic payment using Direct Pay, debit card, credit card or digital wallet and indicate the payment is for an extension. To remit payment, please log in to your MyTax. Use our secure online eCommerce system to pay with a credit card, debit card, or an electronic check. The most important tax deadlines (beyond the April 15th state and federal filing deadlines) are the February 1st Seattle business license tax dates. Seattle businesses that file their city taxes annually now have until April 30 each year to file returns and submit payments due. Please contact the Assessor's Office at 253-798-6111 for more information on how to pay your property tax bill.