I have to file my 91 yr-old aunt's tax return which she is physically unable to sign. I have a Power of Attorney (POA) for her but it does not include her SSN on the document. While reading the instructions for form 2848 on using a substitute POA, I believe I cannot use this POA to sign her tax return on her behalf because of the missing SSN. When reading Pub 216, which is referenced in the instructions, it states that I can rectify the situation by filling out form 2848 & signing the form on my aunt's behalf. Is this the case? Seems odd that I can't sign her tax return using the original POA but can use it to file the IRS POA. Assuming I can do this, when I get to the section for filling out Part II of the form, the designation I would use as her representative is as a family member. However, the instructions state that I must be an "immediate" family member which I technically am not since I am her niece. Can I file Form 2848 & sign it for my aunt as her POA and then send the original POA, a comple ted form 2848 & a statement as to why a non-immediate family member is her POA with her return?