[nommm-nommm]

>Background checks are normally done via a 3rd party background check company, and they don't have access to this kind of data.

Yes they do. There's a company owned by Equifax called The Work Number that collects such information.

https://en.wikipedia.org/wiki/The_Work_Number

[learc83]

The only way The Work Number has access to your salary information is if your employer has given it to them. If your employer is willing to give that out then yes a hiring company can verify your salary.

We are back to my original point that the only way a hiring company can verify salary data is by asking your employer (or having 3rd party ask for them) or forcing you to verify it.