What is the correct address to use for Employers Address on W2

[Matilda]

The address my mother used for her domestic business when applying for her EIN is her home/business.  She still lives there but her mailing address is different now.  Do I put the address that matches her address originally submitted to the IRS when applying for an EIN on W2 forms  or the mailing address used for her business?  

I assume it also has to match the 1040 submitted with her Schedule H.

[TomK2023]

Use the address where you want the IRS to send you tax-related mail.