AdvertisementWhich Business Expenses are Allowed and Which are Disallowed while Filing ITR? Article explains that business taxpayers cannot claim every amount spent during the year as a business expense and that an expense must satisfy prescribed conditions to qualify for deduction. For mixed personal and business expenses, only a reasonable business proportion should be claimed. Can a businessman claim every amount spent during the year as a business expense? Arjuna (Fictional Character): Krishna, in a small business many expenses are partly business and partly personal.