My new employer emailing me the I-9 to fill it out online. In order to complete the form it requires the SSN as well as the green card number. Is it safe to do so online?
I am a notary in the state of Vermont and am sometimes hired to act as an employer's representative and fill out the employer portion of Form I-9. (Despite the fact that anyone the employer trusts, except the new employee, can fill this role and no notarizations are involved.)
It's always possible that your employer has some special version of the form, but typically, it will be one of two types, found on this web page. The first one listed is a PDF fillable form. You type in what can be typed, print it, and hand-write the parts that can't be typed. The employer's representative meets with you and hand-writes the appropriate boxes on page 2. The finished paper form goes in an envelope and is mailed to the employer. This is as secure as your computer is. I don't know you so I don't know if your computer is secure.
The second form listed, "Form I-9 Paper Version (This version is unfillable and must be printed for completion on paper only.) (PDF, 73 KB)", does not allow any fields to be filled in on the computer. You print it. Then you and the employer's representative fill out all the boxes by hand. Then you mail the paper form. With this method, your private information never goes in the computer so there is no electronic risk.