Tax Audit U/S44AB

In a nut shell, if the combined TO crosses 40 lac under one PAN, then that 'person' is bound to come under 44AB.

its clearly written in income tax rule that

every person is liable to have tax audit if

1. carrying on business, if his total turnover, total sales or gross recipts as the case may be exeed  or exeeds to Rs 40 lacs in any previous year.
2. carrying a profession, if gross receipt from prfession exeeds to rs ten lacs in any previous year.

so both of the business shall up into section 44AB 

As per section 44AB, if turnover of any person exceeds 40 lakhs, then the person shall be liable to get audited his books of accounts. examaple : A is running 2 business. Business 1 has turnover of Rs. 60 lakhs and business 2 has turnover of Rs. 10 lakhs. In above case A will be liable to get his accounts audited for both business A and B, though the turnover of Business B is <40 lakhs.