Background Check Advice for First Tech Job

So, I’ve found myself in a not so optimal situation. I recently graduated college and by the Grace of God I got an offer from Google as my first job in the industry. I started working for my current job in 2015 and gave a rough start date estimate on my resume I submitted.

However, when going to acquire exact start dates in the form of tax or legal documentation from my current employer for the background check, I discovered that they had not become an official LLC until December 2017. This is where it all went down hill.

See, I started out as an electrician apprentice, but I was being paid under the table in 2015-2017. Being 14-15 years old at the time, I was not too keen on keeping tax documents or anything. I was also not aware of the legality of it all. I just knew that I would go to work, get money, and run around with friends. So not really knowing what to do, I gave the background check people the date of December 2017.

Lo and behold, the background check company Google uses reported back to Google that they could only verify employment back to 2019 (the company switched to a payroll management company in 2019). Now, both Google and the background check company are requesting legal documentation to 2015 (which I don’t have/never had).

I’m looking for any advice for this situation. Should I just hand in my first payroll check info I received from the payroll company that dates back to 2019 and accept they may change my offer? I’m not entirely sure if I even have tax documents for 2017-2018. Will Google just yoink my offer completely? (I’ve already accepted and am going through onboarding)