If you're unable to complete your Kansas return by the filing deadline, you may request an extension of time to file. If you filed Form 4868 with the Internal Revenue Service for an automatic extension to file, enclose a copy of this form with your completed Form K-40 to automatically receive an extension to file your Kansas return. Kansas does not have a separate extension request form. If you're entitled to a refund, an extension is not required.
To pay the tax balance due for an extension, use the Kansas Payment Voucher (K-40V ). Check the box on the K-40V indicating an extension payment. If you do not pay the tax due (may be estimated) by the original due date, you'll owe interest and penalty on any balance due.