Self Assessment Tax​ 2026: How to Calculate and Pay Online​?

Overview

With ITR filing season for FY 2025-26 (AY 2026-27) now open and the deadline of 31st July 2026 fast approaching, millions of taxpayers are scrambling to calculate and pay their Self Assessment Tax (SAT) before filing their returns. This guide covers everything - what SAT is, how to calculate it, how to pay it online using the e-Pay Tax portal, and how to avoid costly interest and penalties. 

Key Takeaways

• Self Assessment Tax is the balance tax paid after TDS and advance tax for FY 2025-26 before filing your ITR for AY 2026-27.
• It is mandatorily paid under Section 140A before submitting the ITR - no ITR can be filed with outstanding SAT dues.
• Pay via the e-Pay Tax module at incometax.gov.in → Minor Head 300 → AY 2026-27.
• Always include interest under Sections 234A, 234B, and 234C in your SAT payment to avoid further notices.
• Save the challan PDF with BSR Code, Challan Serial Number, and Date of Payment for your ITR.
• The ITR filing deadline for non-audit taxpayers is 31st July 2026.
• If paid while logged in, challan details auto-populate in the ITR within 2–3 working days.

What is Self Assessment Tax?

Self Assessment Tax (SAT) is the balance tax payable by a taxpayer on their assessed income after accounting for Tax Deducted at Source (TDS), Tax Collected at Source (TCS), and advance tax already paid during the financial year.

In simple terms: it is the "top-up" payment you make just before filing your Income Tax Return (ITR) to clear any remaining tax liability. Under Section 140A of the Income-tax Act, 1961 (applicable for AY 2026-27), this tax — along with applicable interest — must be paid before submitting the ITR. You cannot file your return if outstanding Self Assessment Tax remains unpaid.

Key Rule: The Income Tax Return for FY 2025-26 cannot be filed until Self Assessment Tax is fully paid. The e-filing portal will flag any outstanding dues. 

Who Needs to Pay Self Assessment Tax?

You are required to pay Self Assessment Tax if your total tax liability exceeds the sum of TDS, TCS, and advance tax already paid. This commonly applies to:

• Salaried individuals with income from multiple employers or sources not fully covered by TDS
• Freelancers and consultants whose TDS was deducted at a lower rate (e.g., 10%) but whose slab rate is higher
• Business owners and professionals who underpaid advance tax installments
• Individuals with rental income, capital gains (STCG/LTCG), or interest income from FDs/savings accounts not fully TDS-covered
• High-income taxpayers liable to surcharge that was not factored into TDS
• NRIs with Indian-sourced income where TDS was deducted at treaty rates but actual liability is higher

How to Calculate Self Assessment Tax for AY 2026-27?

Calculating your Self Assessment Tax requires a step-by-step approach. Here is the complete formula:

Step 1: Gross Total Income (all heads of income)
Step 2: Less: Deductions / Exemptions (Chapter VI-A or regime-specific)
Step 3: =Taxable Income
Step 4: Apply Slab Rates → Gross Tax Liability
Step 5: Add: Surcharge (if applicable)
Step 6: Add: Education Cess @ 4%
Step 7: Less: Rebate u/s 87A (if eligible)
Step 8: Less: Relief u/s 90 / 90A (DTAA credit, if any)
Step 9: Less: MAT Credit u/s 115JAA (if applicable)
Step 10: Add: Interest u/s 234A + 234B + 234C
Step 11: Less: TDS + TCS + Advance Tax Paid
Step 12: = SELF ASSESSMENT TAX PAYABLE

How to Pay Self Assessment Tax Online - Step-by-Step

The Income Tax Department has migrated tax payments entirely to the e-Pay Tax module on the official e-filing portal (incometax.gov.in). The old NSDL TIN-NSDL route has been replaced. Here is the complete process:

Method A: Pay After Logging In (Recommended)

• Log in to the Income Tax Portal
• Visit incometax.gov.in and log in with your PAN and password.
• Navigate to e-Pay Tax
• On the dashboard, click e-File → e-Pay Tax
• You will land on the e-Pay Tax page.
• Initiate New Payment
• Click on "New Payment" to start a fresh tax payment challan.
• Select the Tax Payment Tile
• On the New Payment page, click "Proceed"
• on the Income Tax tile (not Corporation Tax or others).
• Select Assessment Year and Minor Head
• Choose AY 2026-27 (for income earned in FY 2025-26). 
• Under Type of Payment (Minor Head), select 300 – Self Assessment Tax
• Do not select 100 (Advance Tax) or 400 (Tax on Regular Assessment).
• Enter Tax Breakup
• Fill in the breakup: Tax, Surcharge, and Education Cess in their respective fields. If unsure, you can enter the entire amount under "Tax" — the department will adjust it. Also include any interest payable under Sections 234A, 234B, 234C.
• Select Payment Mode
• Choose your preferred payment method (see Section 6 below) and click Continue.
• Preview and Confirm
• Review all details on the preview screen - PAN, Assessment Year, Minor Head, and amount. Click "Pay Now"
• Accept Terms and Complete Payment
• Accept terms and conditions and click "Submit to Bank"
• Complete the authentication on your bank's portal.
• Save the Challan PDF (CRN)
• On successful payment, you will receive a Challan with a CRN (Challan Reference Number)
• Download and save this PDF - you will need the BSR Code, Challan Serial Number, and Date of Payment to fill in your ITR.

Method B: Pay Without Logging In (Pre-Login)

On the incometax.gov.in homepage, under Quick Links, click e-Pay Tax. Enter your PAN, confirm PAN, and mobile number to receive an OTP. Proceed to fill in the challan details as above. This method is useful if you have forgotten your login credentials.

Payment Modes Available for Self Assessment Tax

Recommended: Net Banking is the most reliable and cost-effective mode for paying Self Assessment Tax. It provides instant confirmation and the CRN/challan details are immediately available for ITR filing. 

Understanding Challan ITNS 280 and the CRN

Historically, Self Assessment Tax was paid using the physical Challan ITNS 280. This form is now fully digitised within the e-Pay Tax module. Key identifiers you need after payment:

These three values - BSR Code, Challan Serial Number, and Date of Payment - are entered in the Tax Payment schedule of your ITR form to claim credit for the Self Assessment Tax paid. If you paid via the portal while logged in, these will auto-populate within 2–3 days.

Critical: Always select Minor Head 300 (Self Assessment Tax) and AY 2026-27 when paying SAT for FY 2025-26. Selecting the wrong Assessment Year is one of the most common errors - it results in tax credit being applied to the wrong year and generates a demand notice.  

Interest and Penalties for Non-Payment of Self Assessment Tax

Failure to pay Self Assessment Tax on time or in full before filing the ITR has significant financial consequences under the Income-tax Act, 1961 (applicable for AY 2026-27).

Section 234A – Interest for Delay in Filing ITR

If the ITR is filed after the due date (31st July 2026 for non-audit cases), interest under Section 234A is charged at 1% per month or part thereof on the amount of tax payable, from the due date until the actual date of filing. Importantly, if Self Assessment Tax is paid before the due date for filing the return, Section 234A interest does not apply on that amount (per CBDT Circular No. 2/2015).

Section 234B – Interest for Shortfall in Advance Tax

If the advance tax paid is less than 90% of the total tax liability during the financial year, interest under Section 234B is levied at 1% per month on the shortfall, from 1st April of the assessment year until the date of actual payment / filing of the ITR.

Section 234C – Interest for Deferment of Advance Tax Instalments

If advance tax installments were not paid on time or were underpaid compared to the prescribed percentages, interest under Section 234C applies at 1% per month for 3 months on each shortfall instalment.

Default Notice Risk: Non-payment of Self Assessment Tax under Section 140A places the taxpayer in default. The Income Tax Department can issue notices, impose penalties under Section 271C, and initiate recovery proceedings. Pay your SAT before filing the ITR to avoid these consequences. 

Important Due Dates for AY 2026-27

Note on Revised Returns: Under the updated framework, the period for filing a revised return has been extended to 12 months from the end of the relevant tax year (i.e., until 31st March 2027 for FY 2025-26). A nominal fee applies for revisions filed after 9 months: ₹5,000 if total income exceeds ₹5 lakh, and ₹1,000 for income below ₹5 lakh. 

FAQs

Is there a last date to pay Self Assessment Tax for AY 2026-27?

There is no separate statutory due date for Self Assessment Tax. However, it must be paid before you file your ITR. For non-audit taxpayers for FY 2025-26, the ITR due date is 31st July 2026 - so your SAT must be paid by then to avoid interest under Section 234A.

Can I pay Self Assessment Tax using UPI?

Yes. UPI is available via the Payment Gateway mode on the e-Pay Tax module. Select "Payment Gateway" on the payment mode screen and choose UPI as the sub-option. Note that only authorised banks (currently Canara Bank, Federal Bank, HDFC, Kotak, Bank of Maharashtra, and SBI) support the Payment Gateway mode.

What is the Minor Head code for Self Assessment Tax?

The Minor Head code for Self Assessment Tax is 300. Do not confuse it with Minor Head 100 (Advance Tax) or Minor Head 400 (Tax on Regular Assessment).

How long does it take for Self Assessment Tax to reflect in Form 26AS?

Tax paid via the e-Pay Tax portal typically reflects in your Form 26AS within 3–5 working days. If you paid through Net Banking or the portal while logged in, the challan details pre-fill in the ITR within 2–3 working days. It is advisable to wait for this reflection before filing your ITR.

What if I paid the wrong Assessment Year for my Self Assessment Tax?

You will need to file a written request with your jurisdictional Assessing Officer (AO) for rectification and reallocation of the challan to the correct Assessment Year. Attach a copy of the challan and a covering letter. This process takes time, so always double-check the AY before payment.

Is Self Assessment Tax applicable under the new Income-tax Act, 2025?

The new Income-tax Act, 2025 becomes effective from Tax Year 2026-27 (i.e., AY 2027-28). For AY 2026-27 (relating to FY 2025-26 income), the Income-tax Act, 1961 provisions - including Section 140A for SAT - continue to apply. The equivalent provision in the 2025 Act will apply from next year onward.

What happens if I file my ITR without paying Self Assessment Tax?

If the ITR is filed without paying the outstanding Self Assessment Tax, the return may be treated as defective under Section 139(9). The tax department will issue a notice giving you a period (usually 15 days) to rectify the defect by paying the tax. If not rectified, the return is treated as if it was never filed.

How is Self Assessment Tax different from Advance Tax?

Advance tax is paid in four installments during the financial year (June, September, December, March) as income is earned - it is a "pay as you earn" mechanism. Self Assessment Tax, by contrast, is paid at the end of the year after the final income is known, to cover any shortfall not addressed by TDS and advance tax. SAT is always paid in AY, before filing ITR.

Can I pay Self Assessment Tax offline at a bank?

Yes. Generate a CRN (Challan Reference Number) online through the e-Pay Tax portal, then visit an authorised bank branch and present it for payment. However, online payment via Net Banking is faster, provides instant confirmation, and auto-populates in your ITR. Offline is recommended only when internet banking is unavailable.