India redesigned its income tax e-filing portal on April 1, 2026. If you last used the old portal (eportal.incometax.gov.in circa 2021-2025), the experience has changed in a few meaningful ways not just the visual refresh, but the actual interaction model.

Here is a developer-and-technically-minded breakdown of what is new.

Karsati: The Portal is Built-In AI Assistant

Karsati is a multilingual AI assistant embedded directly in the e-filing portal interface. It is available in English and Hindi and responds in real time as you navigate filing workflows.

What it does technically:

Contextual guidance: Karsati knows which page you are on. If you are in the ITR-4 income section, it gives ITR-4-specific help, not generic FAQs.
Form selection: Ask Karsati what ITR form you should use, describe your income type (salary + freelance, or business + capital gains), and it recommends the right form.
Field explanations: Click a specific field and ask Karsati what it means. Especially useful for Schedule OS (Other Sources), Schedule CG (Capital Gains), or the newly renumbered sections under the Income Tax Act 2025.
Deadline lookups: You can ask about specific filing deadlines without navigating away from the form.
Karsati does not auto-fill or make entries on your behalf. It is strictly a guidance layer. Think of it as a contextual help sidebar that actually understands the form.

Form Wizard: Guided ITR Selection

Before Karsati, choosing the right ITR form was a lookup exercise: find the instructions PDF, match your income type to the criteria, then start filing. The new portal adds a Form Wizard that walks you through it interactively.

The Wizard asks:

Are you an individual, HUF, firm, company, or trust?
What types of income did you earn this year?
Do you have business income? If yes, are you opting for presumptive taxation?
Do you have capital gains?
At the end, it recommends the correct form and opens it directly. For ITR-1 (salaried) to ITR-4 (presumptive business) transitions, this reduces errors significantly.

Integrated Payment: No More Challan 280 as a Separate Step

Previously, paying self-assessment tax or advance tax required generating a Challan 280 separately on the NSDL/Protean portal, noting the BSR code and challan serial, and entering those in the ITR. The new portal integrates payment directly in the filing workflow.

You can pay via:

Net banking (all major Indian banks)
UPI (BHIM, GPay, PhonePe)
NEFT / RTGS (generates a virtual account number)
Debit card
The challan details auto-populate after payment. This removes a significant source of errors for first-time filers who used to enter the BSR code incorrectly.

What Changed With the Income Tax Act 2025 Renumbering

This is where things get tricky for developers building tax-related tools:

The Income Tax Act 2025 (effective April 1, 2026) replaced the Income Tax Act 1961 with entirely renumbered sections. If you have code that references section numbers in documentation, validation messages, or business logic:

Old 80C (deductions for life insurance, PPF, ELSS) is now in a different section
Old 44AB (tax audit threshold) is now Section 63
Old 44AD (presumptive taxation for businesses) is now Section 58
Old 139 (ITR filing) is now Section 263
CBDT published a conversion table in March 2026. CBDT also issued a corrigendum addressing 76 errors in the first published draft of the new rules. If you are building compliance software, validate against the corrigendum, not just the original Act text.

Pre-Filled Data: What Gets Auto-Loaded

The portal now auto-fills more data than before via three sources:

Form 26AS: TDS deducted by employers, banks, tenants, and others
AIS (Annual Information Statement): Interest, dividends, capital gains from brokers and mutual funds, rental income, foreign remittances
TIS (Taxpayer Information Summary): Simplified aggregate view of AIS data
For an individual filer, most of Schedule TDS, Schedule OS (savings interest), and equity capital gains can now be pre-filled from AIS. You review and confirm rather than enter from scratch.

For business filers (ITR-3, ITR-6), the business income schedules still require manual input or import from accounting software.

The One Friction Point: Section Numbering in Notices

The biggest UX friction in 2026 is that GST notices still reference old section numbers (CGST Act 2017 was not replaced), while income tax notices now reference new Act 2025 sections. If you are building a notice-management tool, you now need to handle two different reference systems for the same taxpayer.

For a full practical guide on navigating the new portal, including the Karsati AI walkthrough, Form Wizard screenshots, and integrated payment steps -- see the detailed guide at Tax Garden: https://taxgarden.in/blog/new-income-tax-efiling-portal-karsati-ai-2026

Tax Garden is a compliance platform for Indian SMEs that handles GST and income tax filing end-to-end. Based in Hyderabad.