ExpressExtension Support Find answers to your questions. Get Answers Support Can I pay the tax dues while electronically filing the extension? What options are available to pay taxes while e-filing Form 7004 with ExpressExtension? When does the payment occur if I opted to pay the IRS tax due through Electronic Federal Tax Payment System (EFTPS)? Need more help? Get in touch with our dedicated support team Contact Us (803) 514-5155 [email protected]