Whatever you pay to have your tax return completed correctly is a pittance compared to the pain in completing it incorrectly . . .
If you have a "simple tax return" (W-2 earnings or Social Security, or both with just interest income, and then use the "Standard Deduction"), you should be fine. However, I am extremely concerned about security! The website that you find may have all of the pictures, logos, data and information that you would expect, but is it a scam, phishing, or fraud? Is the website host in another country?
On par and in conjunction with "security" is "identity theft", the latter can require several years of our time to correct the damages, along with potentially enormous financial costs. It's still on the IRS "Dirty Dozen" list -
Dirty Dozen | Internal Revenue Service
As a tax practitioner, I'm also on the distribution list for mailings from the Federal Trade Commission. It's a huge problem, becoming bigger with the passage of time!
You should not need to send in a copy of your W-2 form. Most tax software requires that the data be transferred or transposed in to the program.
You should always be provided with the hard (printed) or soft copy of your filed tax return.
The contents of these two articles provide excellent summary information regarding the provisions of the new tax laws that became effect January 1, 2018:
Tax Reform 2018 Explained and 2019 Tax Filing Tips | MagnifyMoney
https://www.irs.gov/pub/irs-pdf/p5307.pdf
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