You can go ahead and prepare your tax return and file it. The return can be filed before payment is made. Make the payment before the April deadline. TurboTax will prepare a voucher for you to print and mail with your payment if you choose to mail a check.

Or if you are using the online product, just create an account and go ahead and pay and then finish the return whenever you want to by the deadline. If you are using the CD/download product, go ahead and pay for it and download the product and install it on your computer. You can complete the return whenever you want to by the deadline.