Sorry, Online is closed now so you can not start a new 2018 return or finish one. Oct 15, 2019 was the last day to efile. 2018 is now the prior year.
How to finish a prior year online return
You can only buy the download for prior years. You have to buy a separate program for each year. They only sell the last 3 years. You need a full Windows or Mac computer to install it on. Buy the download here
You have to print and mail prior year returns. When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS received the return. Don’t forget state.
Important! Mail Federal and State in separate envelopes and mail each year in separate envelopes.
If you are getting a refund, there is not a penalty for filing past the deadline. You have 3 years to file for a refund. If you owe taxes, the interest/penalties will be calculated by the IRS based on how much you owe and when they receive your return and payment. The IRS will bill you for this; it will not be calculated by TurboTax.
How to file a prior year
Or If you have a simple return You can fill out the blank forms for free.
Here is the new IRS 2018 Form 1040
And instructions https://www.irs.gov/pub/irs-pdf/i1040gi.pdf
2018 Tax and EIC Tables https://www.irs.gov/pub/irs-pdf/i1040tt.pdf
IRS 2018 Schedules 1 thru 6 (only if needed)
if your online returns are complete there is no need to buy the desktop software. the online versions are in transition. But it may be possible to print just the forms and schedules you need for filing. follow TT filing instructions carefully, use a delivery method where you can track it or get proof of delivery. if you can't access or print the returns wait a day or two and try again.
then follow VolvoGirl's instructions for mailing.