Income Tax Compliance Calendar September 2026: Key Due Dates

Yes, but only when the related income is included in the estimated taxable income and the payer has actually deducted or collected tax on that income. Section 405 does not allow a reduction merely because TDS or TCS is expected to arise later.

Section 425 applies to deferment or short payment of individual advance-tax installments. Section 424 applies where the total advance tax paid is less than 90% of the assessed tax. A taxpayer can therefore incur interest under both sections for separate advance-tax defaults.

No. Paying at least the prescribed tolerance percentage may prevent installment interest under Section 425 for that stage. It does not remove interest under Section 424 where the total advance tax paid remains below 90% of the assessed tax at the end of the tax year.

Not always. Section 425 provides relief where the shortfall arises from specified income that could not be estimated earlier, such as capital gains, dividend income or qualifying business income. The related tax must be paid in the remaining installments or within the prescribed final-payment timeline.

Yes. A taxpayer may revise the estimate of current income and adjust the remaining advance-tax installments where profits, capital gains, deductions, TDS credits or other taxable income change. The revised computation should include tax already paid and the updated liability for the tax year.

Yes. The deductor may furnish Form 149 with an accountant’s certificate confirming that the deductee filed the return, included the relevant income and paid the applicable tax. Interest remains payable from the date tax was deductible until the deductee furnished the return.

The collector may submit Form 150 under Section 398(2). The accountant must certify that the collectee filed the return, considered the relevant amount while computing income and paid the applicable tax. Acceptance removes assessee-in-default status, but the prescribed interest liability continues.

No. Where accounts are audited under another law, the taxpayer must still furnish the particulars prescribed under Section 63. Parts A, B and C of Form 26 apply in such cases, with Part C containing the audit report for accounts audited under another law.

Ebizfiling can reconcile estimated business income, capital gains, special-rate income, deductions, TDS, TCS and advance tax already paid. This helps identify instalment-level shortfalls, year-end exposure and potential interest under Sections 424 and 425 before the next tax payment.

Yes. Ebizfiling can assist with transaction review, document preparation, accountant coordination and filing support for Form 26 tax audits. It can also support Form 149 and Form 150 compliance where relief is sought from TDS or TCS assessee-in-default status.