STOP!  WAIT!  Do not use your paystub to fill out the W2.  You need to use the actual W2.  Your paystub won't match the W2.  There are several items that affect the amounts.  Most people that use the paystub have to send in an Amended return later.  Your employer has until Feb 1 to send it to you.  And there's no hurry to file.  

Even if Turbo Tax lets you submit your return they will just hold all the returns until the IRS opens filing on Jan 27, 2021 or later.  So there is no hurry.  And a lot of people who file early find out they have to amend later like when they get their actual W2 and 1099 forms.  Or they get more forms than they were expecting.  

And You should wait because you might get a late W2 or 1099 in the mail.  They have until Jan 31 to send you the tax forms.  Or they may send you a corrected W2 or 1099 even later.

how can you get it? two choices:

1) wait for it to arrive as your employer has until Jan 31 to get it to you by law

2) ask your employer 

DO NOT FILE WITHOUT THE W-2 in your possession.  The IRS is not going to accept your return any earlier than Jan 27

"Haste Makes Waste"

Wait for your W-2.   If you try to guess what to put in the boxes for a W-2 from a pay stub it will be wrong.  Your pay stub and the W-2 will not match.  Employers have until February 1 to issue W-2's.  The IRS will not be accepting returns until the end of January.  There is no reason to e-file early with incorrect information, unless you want to spend months waiting while you have an amended return being processed.

Please be careful about being in too much of a hurry to file your next tax return. Many tax forms are not available at the very beginning of the tax season, so you have to wait for your forms. The software still needs updates at the beginning of the tax season. 

The IRS will not begin to accept the e-files until almost the end of January.  So  even if you e-file before that, your return just sits on the server.  If you realize that you made a mistake or left something out—as many people do—you cannot change it.

Every year we see people who are in such a rush to file that they file incorrectly and incompletely.  If you file too early and leave out a W-2 or a 1099, or forget to enter information, you will end up having to amend your tax return---and that takes months.  Employers have until February1. 2021 to issue W-2's----and ALL of your 2020 W-2's have to be on the same tax return.  Many of the 1099's and 1098's you need do not arrive until late January or sometime in February.  If you are getting Earned Income Credit or Additional Child Tax Credit, the IRS is going to hold your refund until the end of February no matter how early you file.  There seems to be a greater chance of "early" returns being reviewed and those refunds are delayed, or early returns are more often subject to identity verification--which will also delay processing.  Filing too early may just be a recipe for a delayed refund.  It might go more smoothly for you if you wait until at least mid-February to file instead of e-filing during the first minute that you can do it.

https://ttlc.intuit.com/community/tax-topics/help/how-will-the-stimulus-package-impact-me/00/1393859

We know that the IRS is already revising the 2020 Form 1040 because of the 2nd stimulus.   That means all tax preparation software programs will also have to be re-programmed and updated.  Those changes could take until sometime in late January or even longer—we do not know yet.    Do NOT be in a hurry to file your 2020 tax return until more is known.   It is never a good idea to file too early; filing your 2020 return too soon may result in a lot of extra confusion that can be avoided if you wait and file a little later.