Maintenance of books of account: record keeping duty for specified professions and businesses; Board to prescribe particulars and retention.
Section 62 requires maintenance of books and documents to enable computation of total income by specified professions, businesses meeting alternative income or turnover tests, and professions notified by the Board. The Board may prescribe the form, particulars, manner, place and retention periods. The enacted text repositions the Board's notification power into the definition of specified professions, corrects an apparent turnover threshold error for individuals/HUFs, and revises cross references affecting deemed profits carve outs; operational details depend on subsequent rules and the referenced tables.

Presumptive taxation for non resident activities fixes taxable profits on defined receipts and narrows audit relief.
Section 61 prescribes a presumptive taxation method for six specified non resident activities, fixing taxable profits as percentages of defined receipts (A and B) and supplying definitions and examples for those receipts; it bars deductions or losses against income so computed, prescribes written down value treatment, and permits audit based claims of lower actual profits only where expressly allowed and subject to strict bookkeeping and audit compliance, while the Act narrows those reliefs and clarifies definitional and non application provisions.

Presumptive taxation regime clarified for small businesses and goods carriage operators, altering computation and compliance timing.
Section 58 creates a presumptive taxation regime for small businesses, goods carriage operations and specified professions, prescribing turnover limits and fixed presumptive computation methods. Taxpayers may elect actual profits but must maintain books and obtain an audit if total income exceeds the basic exemption limit. The enacted text clarifies that receipts received by specified banking or online modes count for a lower percentage only if received during the tax year or before the due date, treats non account payee cheques/bank drafts as cash for cash tests, and expressly excludes goods carriage receipts from aggregation for monetary limits under book keeping/audit rules.

Deemed consideration: stamp duty value may be treated as full value where declared consideration is lower.
The provision deems the stamp duty value to be the full value of consideration for transfers of non-capital land or buildings where declared consideration is below stamp duty value, subject to a statutory tolerance that preserves actual consideration if stamp duty value is within a specified margin; agreement date stamp valuations may be used when agreement and registration dates differ provided consideration (or part) was received by specified banking/online modes on or before the agreement date, with determination mechanics governed by cross referenced valuation rules.

Amortisation rules for telecom spectrum and licence fees require time spread deductions and proceeds offset on transfer.
The section prescribes amortisation in equal instalments for four categories of expenditure-amalgamation/demerger costs, SVR payments, spectrum fees and licence fees-starting from specified initial tax years (event/payment or later of business commencement/payment) and, for spectrum/licence, running co terminous with the life of the right. Transfers of spectrum/licence rights trigger offsetting of proceeds against remaining unallowed expenditure with specified income inclusion rules and a formula for part transfers; amalgamation/demerger transfers to an Indian company preserve the section's application to the successor. Depreciation exclusion and reassessment mechanics for wrongful allowance are also provided.

Amortisation of prospecting expenditure permits staged tax deduction subject to funding reductions, exclusions and audit conditions.
Amortisation allows an Indian company or resident (other than a company) engaged in prospecting for specified minerals to capitalise qualifying expenditure incurred in the year of commercial production and up to four preceding years, claim periodic instalments after reducing amounts funded by others and realizations (sale, salvage, compensation, insurance), and excluding site/deposit acquisitions and depreciable capital assets; instalments are limited so as not to reduce income from commercial exploitation below nil, unallowed amounts may be carried forward within the overall amortisation period, and audit and prescribed reporting are required for non-company assessees.

Site restoration fund deductions for petroleum operations, with recapture on asset disposals governed by Schedule X.
Section 49 creates a Site Restoration Fund regime for petroleum and natural gas operations under a Central Government agreement, allowing deductions for deposits to a designated special account or site restoration account with computation governed by Schedule X. Withdrawals or transfers from those accounts are taxable in the year of withdrawal/transfer under Schedule X. The Act removes a clause in the Bill that explicitly deemed a portion of asset cost relatable to prior deductions as business income on sale within a specified holding period, instead delegating disposal and recapture rules to Schedule X.

Recapture on premature disposal reverses deduction for deposits into designated tea, coffee and rubber development accounts, taxing attributable cost on disposal.
Clause 48 permits a deduction for deposits into designated tea, coffee and rubber development accounts, with computation governed by Schedule IX; withdrawals or transfers are chargeable to tax in the year of transfer/withdrawal as per Schedule IX, and disposal of assets acquired under the scheme within the protective holding period results in deeming that portion of the asset cost attributable to earlier deductions as business income in the year of sale or transfer.

Immediate deduction of capital expenditure for specified businesses, subject to conditions, approvals and an eight-year recapture rule.
The Act permits an elective immediate deduction of whole capital expenditure incurred wholly and exclusively for specified businesses in the year of incurrence (or in year of commencement if pre-commencement cost is capitalised), subject to specified commencement dates, definitions and conditions. The deduction is disallowed where a business is formed by splitting/reconstruction or by transfer of previously used machinery (except a limited de minimis exception), requires specified approvals/notifications for certain sectors, excludes land/goodwill/financial instruments and cash over prescribed limits, and is subject to an eight-year sole-use recapture mechanism with depreciation adjustment.

Scientific research deductions conditional on prescribed authority certification, approval for in-house R&D, and prohibition on duplicate claims.
The provision allows deductions for capital and revenue expenditure on business-related scientific research, excluding land costs, and deems qualifying pre-commencement salaries, materials and capital costs to the year of commencement if certified by the prescribed authority. In-house R&D deductions are available for prescribed companies with approved facilities and qualifying costs subject to prescribed conditions and documentation. Payments to approved research entities are deductible only for approved programmes and recipients. Non-duplication rules bar claiming the same expenditure under other provisions and exclude parallel asset-based deductions where research deductions have been taken.

Amortisation of preliminary expenses allows spreading eligible start-up costs over successive years subject to statutory cap and compliance conditions.
The provision permits amortisation of specified preliminary and project-related expenditures by resident Indian assessees through equal annual deductions over five successive tax years beginning with the year the undertaking becomes operational or the year of commencement. Eligible items include feasibility and project reports, market surveys, engineering services, specified legal and registration costs, prospectus and public issue expenses for companies, and other prescribed items not deductible under any other provision. A statutory cap restricts the allowable deduction to a percentage of project cost or capital employed, with project cost tied to actual cost as shown in the books, and procedural conditions require prescribed filings and audited accounts for certain taxpayers.

Capitalising foreign exchange fluctuation adjusts asset cost to reflect exchange-rate differences between acquisition and payment.
Section 42 requires capitalisation of foreign exchange variation by computing A = B - C, where B is INR paid during the tax year (excluding parts met by others) for asset cost or repayment of foreign-currency borrowings used to acquire the asset, and C is the INR liability corresponding to that payment at acquisition; the variation is added to or deducted from the asset's actual cost, specified capital expenditure categories, or cost of acquisition for set-off purposes, with forward-contract-covered amounts computed at the contract rate.

Written down value rules: formulaic WDV computation and continuity across specified corporate transfers ensure consistent depreciation treatment.
Computation of written down value uses three treatments: actual cost for assets acquired in the year; actual cost less depreciation actually allowed for assets acquired earlier; and block computation by [(A - D) + B - C] - E with statutory caps. The provision maps WDV/actual-cost continuity across specified corporate transfers (holding/subsidiary, amalgamation, demerger, LLP conversion, corporatisation), deems carried-forward depreciation to be depreciation actually allowed, and requires revaluation/book-depreciation adjustments where earlier years lacked tax computation.

Cost of acquisition continuity: transferee inherits transferor's cost plus improvements and transfer expenses for stock-in-trade sales.
When an asset received on amalgamation, by gift, will, irrevocable trust, or HUF partition is sold as stock-in-trade, the transferee's cost of acquisition is the sum of the transferor's original cost, any cost of improvement, and any expenditure incurred by the transferor or amalgamating company wholly and exclusively in connection with the transfer; certain assets are excluded by separate statutory provision and no alternative valuation or evidentiary rules are provided.

Computation of actual cost: adjustments for third party funding and input tax credits limit depreciable base.
Section 39 defines actual cost for assets used in business or profession as the assessee's cost reduced by amounts borne by another person, GST/input tax credits where claimed and allowed, excise/additional customs duty credits where claimed and allowed, and any subsidy, grant or reimbursement relatable to acquisition; it excludes payments made outside prescribed banking/online modes beyond the daily threshold and prescribes a formula to apportion non asset specific subsidies across assets.

Recapture of previously claimed deductions: reversals, recoveries and asset disposals treated as business income under tax law.
Certain receipts are deemed profits and gains where they reverse or offset earlier deductions or allowances: remission or cessation of trading liabilities; gains on disposal of tangible assets where proceeds plus scrap value exceed written down value; sale of research capital assets sold without other use where proceeds plus prior deductions exceed capital expenditure; recoveries of bad debts previously deducted; and withdrawals from special reserves previously deducted. Applicability requires that the earlier allowance was made in assessment, assets were used for business or profession with depreciation claimed and allowed, and research assets were not used for other purposes; successors in business are within scope.

Actual-payment rule: deductions are taxable only when actually paid, with narrow early-payment carve-outs and contractual limits.
Section 37 makes specified business deductions allowable only in the tax year in which they are actually paid, regardless of accounting method or when liability arose. Enumerated categories include statutory levies, employer fund contributions, leave-in-lieu payments, amounts referred to section 32(a), interest on loans/advances/borrowings from specified financial entities, payments to Indian Railways, and late payments to micro and small enterprises; limited exceptions permit earlier-year deduction if paid by the return filing due date (excluding MSME payments), and conversion of interest into deferred instruments is not treated as payment.

Restrictions on deductions for related party payments require arm's length pricing and specified electronic payment modes for eligibility.
Section 36 empowers the Assessing Officer to disallow payments to specified persons that are excessive or unreasonable relative to fair market value, legitimate business needs, or benefit to the assessee; defines specified persons and a 20% substantial interest test; prohibits deductibility of aggregate cash payments in a day above prescribed thresholds unless made through specified banking/online modes (with a higher threshold for carriage services); treats subsequent cash payments as business income where deduction had been earlier allowed; and adds an exclusion for marked to market or expected losses except as expressly allowable.

Non-deductibility for unpaid withholding taxes: deductions denied until the required tax or equalisation levy is paid.
Section 35 conditions deduction of business or professional expenses on compliance with withholding and levy obligations: where tax or equalisation levy required to be deducted or paid is not timely deducted/paid, a specified portion of the payment is disallowed in the year of non-compliance and is allowed only in the year when the tax or levy is actually deducted and paid; parallel deeming rules and provisos address later deduction/payment and certain default scenarios, while partnership and association rules restrict deduction for unauthorised or excessive partner/member remuneration and interest.

Deduction for depreciation: statutory framework limits and special incentives for qualifying business assets under the tax code.
Section 33 provides for deduction for depreciation on tangible and specified intangible assets used wholly and exclusively for business or profession, excluding goodwill; it prescribes computation by blocks and prescribed rates, applies special rules for power undertakings and leasehold improvements, imposes a 50% restriction for assets first used less than 180 days, allows an additional first-year deduction for qualifying new plant and machinery subject to strict conditions, and prescribes pro rata allocation and ceilings on claims in succession, amalgamation or demerger with carry-forward rules for unallowed depreciation.