Doing Tax Audit & computing the tax liability are two different aspects. Tax Audit involves only of auditing the entities Books of accounts to confirm that they are in compliance with the tax laws. All the payments/expenses/incomes etc.. are being supported by proper & sufficient documents. All the assets of the entity are being properly valued & liabilities are being properly stated. After that an Tax Audit Report is being issued by the Tax Auditor to the entity.
After the above is being done, then the task of computing the tax liability of the entity is being performed.
Statutory Audit is different from Tax Audit. SA is being performed if there is an requirement of Audit under any law. For instance under the Companies Act, the co is required to get it’s books of accounts audited from the Statutory Auditor say quarterly, half-yearly or yearly depending upon the size of the entity. The statutory Auditor verifies if all the requirements as laid down under the Co’s Act are being complied by the Company. After that the Statutory Auditor issues an Audit Report to the Company.
In case of companies where Statutory Audit is being performed, there is no need to perform a separate Tax Audit, as there is an requirement under the Co’s Act to get the books of acoc*nts audited by the Statutory Auditor. In such case the Stat Suditor also can perform Tax Audit & he then issues an Tax Audit Report, Statutory Audit Report & also computes the Tax liability.