A unit employing about 25 employees is not a "very small" unit.
As a normal practice, even in proprietorship concerns, the account books, namely ledgers, cash books, vouchers/bills, etc., are maintained by the employers. Without maintaining account books, it is unclear how assessments under the Income Tax Act, Sales Tax, Excise, etc., if applicable, are being done in respect of your establishment. Without the production of such account books, including cash books, trial balance, and vouchers, etc. (as mentioned by Sh. Dahiya ji in his remarks above), concerning expenses of the unit, no inspecting authority will certify that the contribution under respective laws has been paid correctly.
It is a common practice that the names and wages/salaries paid to employees are not generally reflected in the Wages Registers as maintained and produced. In the majority of cases, the amounts paid to contractors, casual employees, temporary employees, etc., are booked directly in the account books of the unit.
The ESI Social Security Officer as well as the Inspecting Officer of EPFO will issue letters/show cause notice for the production/non-production of account books, and it will be for the management of such a "very small" unit to justify non-maintenance of such records.
Non-production of records, including Account Books, is an offense punishable under the above Acts and rules/regulations framed thereunder.