I started working as an independent contractor for DoorDash in late march, missing the deadline for the first 1040-ES payment. Can I just start filing these mid year?

The 1040ES are basically optional to pay.  And this year with Covid-19 the first one isn't due until July 15.

To prepare estimates for next year you start with your current return, but be careful not to change anything.  For Online returns, if you can't get back into your return, Click on Add a State to let you back into your retun.

You can just type W4 in the search box at the top of your return , click on Find. Then Click on Jump To and it will take you to the estimated tax payments section. Say no to changing your W-4 and the next screen will start the estimated taxes section.

Or Go to….

Federal Taxes or Personal (Desktop H&B)

Other Tax Situations

Other Tax Forms

Form W-4 and Estimated Taxes - Click the Start or Update button

Or Here are the blank Estimates and instructions…..

http://www.irs.gov/pub/irs-pdf/f1040es.pdf

The 1040ES quarterly estimates are due April 15, 2020, June 15, Sept 15 and Jan 15, 2021.   The first quarter isnot due until July 15 this year.  Your state will also have their own estimate forms.

Or you can pay directly on the IRS website https://www.irs.gov/payments

Be sure to pick the right kind of payment and year.....2020 Estimate