Should I file my extended 2018 return now if I plan to amend 2017, and the amended numbers will affect the 2018 return? or wait for Amended to be processed.

[mvk_atl]

I know it can take up to 16 weeks to process an amended return. The 2018 numbers would be different from what I thought when I filed the extension and paid, because of the 2017 change.  If I file my extended 2018 return now, it will line up with my already filed 2017 but not the new numbers in the amended. The IRS might get the amended processed before the Oct 15 2019 deadline for this year's return, in which case I can file a 2018 return based on amended 2017, but if not, should I file 2018 based on the original processed return and then have to amend 2018 too?  I would probably have to overpay if I do that.

[DoninGA]

The extension you filed for the 2018 tax return is only for tax year 2018.  There are no extensions for tax year 2019 or tax returns for tax year 2019 until the end of the 2019 tax year after 12/31/2019.

If you have already filed the 2018 tax return, received the 2018 tax refund or paid the 2018 taxes owed, and you need to make changes to the filed 2018 return, then file an amended tax return.

Any tax data changed on the amended 2018 tax return where there is a carry-over to the 2019 return should be reflected on the 2019 return when it is filed in 2020.

[mvk_atl]

I edited to correct my year dates - I extended the 2018 return, plan to amend 2017 return. I am concerned about filing my extended 2018, which was based on TTax pulling in the originally filed data from 2017, before the IRS has a chance to process the Amended 2017.  I will need to re-do 2018 which has NOT yet been filed. Is it best to:

(a) file2017 amended now (because I want to minimize penalty/interest)  as well as file 2018 now based on the original 2017 numbers (I've already prepared that).

(b) File amended 2017 now and wait to see if Amended gets processed by Oct 15 2019 extension deadline and only then, file a 2018 based on the Amended numbers (I have to redo the whole 2018 return from scratch by pulling in Amended numbers).

(c) go ahead and file the Extended 2018 now, which is already prepared based on original 2017 numbers, and then amend both 2017 and 2018 later.

[Texas Roger · Accepted solution]

I suggest you go ahead and amend your 2017 return and mail it. You can go ahead and transfer the 2017 amended data into your 2018 return when you start it and go ahead and complete it. You can wait until near the Oct. 15 deadline for filing a 2018 return with extension.

If your 2017 amended return isn't processed by then, go ahead and file your 2018 return in the hopes that the IRS will not make any changes to your 2017 amended return. If the IRS processes your 2017 amended return before Oct. 15 and does make changes, you can make any changes to your 2018 return caused by the IRS changes to your 2017 amended return before you file it. 

If you expect to owe any tax on your 2018 return, you were required to pay those estimated taxes when you filed for the extension by April 15. If you didn't you will be incurring underpayment penalties the longer you wait to file.