here are the options for residency. it's actually pretty lenient IMO
Two of the following, and the must be from different catagories (a-o)
a) Unexpired SC driver’s license, beginner’s permit, ID, or vehicle registration: must show your current residential address or your updated address must be on file within the SCDMV’s system if it is not reflected on your credential.
b) Unexpired SC Concealed Weapons Permit (CWP).
c) County tax bill or property tax receipt for your residence (current or preceding calendar year) Must be mailed to your SC address.
d) State or federal tax records Income tax returns for current or prior year are acceptable including electronic tax file or W2. You must be listed as a primary tax payer or dependent.
e) School records - must be from an SC school, college or university (current or prior school year).
If presenting one of the following items, it cannot be more than 90 days old.
f) Utility bill for services at your current SC residence (mailed to your SC address, not an out-of-state address): may be a water, sewer, gas and electricity, cable/satellite TV, internet, cell phone, or telephone bill.
g) Financial statements: credit card or bank statement or signed letter on bank letterhead: must also show your name and SC physical address as the account holder.
h) Home mortgage monthly statement or deed.
i) Social security check or annual statement.
j) Insurance documentation from a company licensed to do business in SC:
Automobile or life insurance bill (cards or policies are not accepted).
Homeowner’s insurance policy or bill, (unclear if tenant insurance counts)
k) Current letter of employment or payroll stub/statement from an SC or out-of-state employer.
l) US Postal Service letter or item delivered by the US Post Office:
m) Parolee letter from parole officer.
n) Other documents issued by federal/state/municipal government.
o) Letter from director of SC social welfare institution (such as a homeless shelter, battered women’s shelter, halfway house, group home, orphanage) stating you are a resident of the facility.
a retiree could use: SS check, Postal Service Letter, "other federal/state/municipal" documents, Financial Statement, or a tax return