How do I get my preparer signature on Form 3115 for an automatic change request, Part I of the form?
Part I, Information for Automatic Change Request, does not require the preparer's signature.
"Preparer (other than filer/applicant). If the individual
preparing Form 3115 is not the filer or applicant, the preparer
also must sign, and include the firm's name, where applicable.
Generally, for both automatic and non-automatic changes, the
preparer (if not the filer or applicant) must sign the original and
copies of Form 3115. If Form 3115 is e-filed, the preparer need
not sign the original e-filed Form 3115 but must still complete the
preparer information and, if applicable, must sign the duplicate
automatic Form 3115 copy."
Instructions for Form 3115, page 3.
However, if you want to sign the form, since it must be attached as a PDF, you can print and sign it, and then scan it to PDF for attachment.