Security deposit maintenance requires exchanges to preserve issuer deposits and enforce or renew bank guarantees promptly. Stock exchanges must ensure issuer companies maintain the required security deposit before opening subscription lists and keep it intact; they must recoup shortfalls from expired bank guarantees by obtaining cash or fresh/renewed guarantees, implement a tracking system with alerts at least one month before guarantee expiry, and invoke guarantees if issuers fail to restore deposits within the specified timeframe. Exchanges may not adjust the security deposit against any dues of the issuer and must implement these directions within the regulator-prescribed compliance period.