How many times can I file my taxes within a year

[fanfare]

Just once. For best results, make sure it is correct and complete.

[VolvoGirl]

Please explain what you mean. File what taxes?  You file one tax return for the prior year ending each Dec 31.  Your tax return is due by April 15 each year.  You can ask for a 6 month extension  until Oct 15.  But any tax due is due by April 15.

[Marquise]

What if I forgot to file a w2 on my taxes this ?? I was wondering if I could file that w2 even tho I filed my taxes already 

[VolvoGirl]

You cannot change or add anything on the return that you e-filed.  It is too late, just like when you put an envelope in a US mailbox

Now you have to wait until the IRS either rejects or accepts your return. If your return is rejected, you will be able to go into your account and add or change it and resend it.

If the IRS accepts your return, then you have to wait until it has been fully processed and you have received your refund or paid the tax due. THEN you can prepare an amended tax return 1040X and mail it in. You cannot e-file an amended return.  Meanwhile, DO NOT change anything on your return until you start the amended return. If you did change or add the missing info then take it out and put your return back to the way it was when you first filed it.

You can check your efiling status here,
https://turbotax.intuit.com/tax-tools/efile-status-lookup/

How to amend an Online return
https://ttlc.intuit.com/community/amending/help/how-do-i-amend-my-turbotax-online-return/00/27577

[KAM_2018]

I already file my taxes for my first job. But my other job taxes just came. Can I file them.

[DMarkM1]

Not yet.  You are supposed to wait for all W2s and tax forms and file them all on one tax return for the year.  Since you have already filed you will need to wait for that return to process and then amend it to add the additional income.  

The IRS normally catches W2 errors/omissions.  They will likely send you a letter letting you know of the discrepancy and giving you instructions to correct it.  

If you don't get a letter, but your refund is deposited in your account, that will be an indication that your return has been processed and you can do the amendment.

When you amend here is a helpful link.