Section 145(3) of the Income Tax Act

The Assessing Officer loses jurisdiction and the entire reassessment becomes invalid if no addition is made in respect of the income that formed the basis of the reopening. Explanation 3 to Section 147 does not permit assessing other escaped income unless an addition is made for the original income forming the reason to believe.

Where purchases are found to be non-genuine or fictitious, a reasonable disallowance of 25% of such purchases or the peak credit, whichever is higher, can be made. This is applied to address unexplained expenditure under Section 69C when actual goods are likely procured from the grey market.

In a best judgment assessment, some guesswork is inherent, but the estimate must be fair and not arbitrary. Books of account can be rejected under Section 145(3) if the assessee fails to substantiate entries or prove the genuineness of transactions, leading to estimation of income.

If there is an unexplained cash credit, the Assessing Officer can treat it as the assessee's income, even when the income is finalized on an estimation basis, without proving its specific source. The onus then shifts to the assessee to prove that the income represented by the cash credit has already been taxed.

The Supreme Court established principles for best judgment assessments, stating that some guesswork is inevitable but the assessment must be bona fide, rational, and free from bias or capriciousness. An appellate authority cannot substitute its judgment for that of the Assessing Officer unless the AO's assessment is shown to be biased, irrational, vindictive, or capricious, especially when the assessee fails to provide proper accounts or counter-evidence.

When making an addition for unaccounted receipts, on-money, or non-genuine purchases/sales, the addition should be restricted to the estimated profit element embedded in such transactions, rather than the entire gross amount, particularly when evidence of corresponding expenditure is incomplete. This estimation often involves applying a net profit rate.

The project completion method and the percentage of completion method are both recognized methods for recognizing income from real estate contracts.

The Assessing Officer has a duty to examine whether an assessee's books of account truly disclose the correct income and is not bound to accept the accounting system regularly employed by the assessee or methods followed in earlier years. Each assessment year is a distinct and self-contained unit for tax purposes.

Penalty under section 271(1)(c) cannot be levied when an addition to income is made on an estimated basis without concrete evidence of concealment or furnishing inaccurate particulars of income. The provisions of section 271(1)(c) are not attracted to cases where income is assessed on an estimate basis.