Properietory firm

Personal expenses cannot be booked in business

Yes you can take the expense of proprietor in the book of business but care should be taken that the expense is related to business, Personal expense is disallowed.

You cannot take exp. Of proprietor in books of firm if they are of personal nature. 

However ,if expenses are related to business then they can be taken up in books.

Only Business Expenses can be claimed (taken in the books of firm).. You must check the business connection of each expense.

The Income Tax return will b filed by clubbing the income of proprietor & proprietorship firm. So its better to show the personal exp. of proprietor in his/her personal books.