Hi Robert,
Conceptually, benefit of CENVAT is available only when there is a cascading effect (i.e. tax on tax) which is an effect where both inputs and outputs are taxed. In your given example, your output service is exempt upto 10 lakh so the right of CENVAT Credit upto that amount never arises. Now, if it never arises then, obviously, you can not avail that Credit even at subsequent time i.e. once you cross limit of 10 lakh and pay Service Tax.
Discussion leads to an end that upto 10 lakh a SSP is required to bare CENVAT and can avail exemption benefit. After that limit, enjoy CENVAT and pay ST.
You read bare text of Notification No. 6/2005 dated 01.03.2005 and specially point no. 2(ii), (iii), and (iv) which are reproduced below for your easy reference:
"2. The exemption contained in this notification shall apply subject to the following conditions, namely:-
Hope your query will come to an end.
Warm Regards.
(i) the provider of taxable service has the option not to avail the exemption contained in this notification and pay service tax on the taxable services provided by him and such option, once exercised in a financial year, shall not be withdrawn during the remaining part of such financial year;
(ii) the provider of taxable service shall not avail the CENVAT credit of service tax paid on any input services, under rule 3 or rule 13 of the CENVAT Credit Rules, 2004 (herein after referred to as the said rules), used for providing the said taxable service, for which exemption from payment of service tax under this notification is availed of;
(iii) the provider of taxable service shall not avail the CENVAT credit under rule 3 of the said rules, on capital goods received in the premises of provider of such taxable service during the period in which the service provider avails exemption from payment of service tax under this notification;
(iv) the provider of taxable service shall avail the CENVAT credit only on such inputs or input services received, on or after the date on which the service provider starts paying service tax, and used for the provision of taxable services for which service tax is payable;"