In short
What a net worth certificate for a loan is
A net worth certificate for a bank loan is a chartered accountant's certified statement of one person's assets and liabilities as at one date, with the net figure, prepared for the lender named on it. The person is whoever the credit team is relying on: the borrower, a co-applicant, a joint holder of the security or a guarantor. Assets are stated on a disclosed basis, every borrowing and charge is set against the asset it secures, and the certificate carries a UDIN the branch can check without contacting you.
It is one input into a credit file, not the file. It is not a credit appraisal and reaches no view on eligibility or sanction. It is not a valuation report: property and unlisted holdings are stated on a basis the certificate names, which the lender may accept, discount or value for itself. And it confirms no asset as free of charge beyond the records examined. For what a net worth certificate is in general, who issues one and how the figure is computed, see the net worth certificate page; for the reading a credit team gives the figure once it is in the file, see how a credit team actually reads the figure.