Retirement tax questions

Hi, Minh, and thank you for the reply and sharing the link.

 

It looks like in order to open a Solo 401k I would be required to get an EIN, regardless of state?  

 

If I do switch over to an EIN, I'm just not clear on how the EIN will link to my income when I file taxes using my SSN.

 

The only reason I would do the EIN is to have the ability to create the Solo 401k.

 

Thank you for any additional expertise you may have to share.