Sir/Mam,
A person has taken Centralised registration for service tax and now he wants to take separate registration for his head office and branches. What procedure should he follow?
write an application to your concerned commissioner with form st-1 stating the changes reqd. he shall amend the certificate of registration and issue fresh certificate in st-2. later you can apply for s.tax registration branchwise.
application to be filed manually whereas st-1 is filed online. after filing st-1, take out its printout and then submit. in your case, no documents would be reqd. however if any document would be reqd then officials will inform you there.