Surrender of registration Certificate: in following circumstance an assessee may immediately make an application for surrender of Registration:

1. Transfer of business to another person (rule 4(6), Service Tax Rules 1994)
2. Ceases to provide taxable service

Non-surrender of Registration Certificate does not attract any penal action. But it is, advisable to surrender the same, as till assessee is registered, he/she is mandatorily required to file the return. Failure of which attracts penal provision.
(Please Refer: Rule 4(7), Service Tax Rules, 1994)

After ascertaining that all monies due to the department has been paid by the assessee the Superintendent shall cancel the registration. Till such cancellation happens the assessee has to file all returns, failure of which may attract penalty.(rule 4(7), 4(8), Service Tax Rules 1994.

The superintendent has to check the books of the assessee to ascertain that no money is due to department from the assessee. In this regard a certificate from a charted accountant could help.