Portal was broken, but self-assessment still binds the taxpayer.

Bharti Airtel’s GST Overpayment: When the Portal Failed, Did the Law Follow?

When the Goods and Services Tax (GST) regime launched in July 2017, Bharti Airtel Ltd. was among the first to file its returns. The company used the government’s new electronic portal, filing Form GSTR-3B for July, August, and September 2017. But the portal was broken. Auto-populated forms like GSTR-2A—designed to show input tax credits (ITC) available from suppliers—were not yet operational. So Bharti Airtel did what any prudent taxpayer would: it paid its entire tax liability in cash. The result? An overpayment of approximately Rs.923 crores.

When GSTR-2A finally went live in September 2018, the company discovered the error. It wanted to rectify its original GSTR-3B returns to claim the ITC it had missed. But a government circular dated December 29, 2017, stood in the way. Paragraph 4 of that circular restricted rectification to subsequent months only—not the original error period. The Delhi High Court read down that circular, allowing Bharti Airtel to go back and fix its July-September 2017 returns. The Union of India appealed to the Supreme Court. At stake: not just a large sum for one company, but the fundamental question of whether a taxpayer’s right to rectify returns can be curtailed by a government circular when the government’s own portal is non-functional.

The GST Launch: A Portal That Wasn’t Ready

The GST regime—a landmark in cooperative federalism under Article 246A of the Constitution—was rolled out on July 1, 2017. The government introduced a stop-gap return filing mechanism under Rule 61(5) of the CGST Rules, 2017. This was Form GSTR-3B: a simplified, summary return. The idea was that taxpayers would file GSTR-3B monthly, and later reconcile it with the detailed GSTR-1 (outward supplies) and GSTR-2A (inward supplies) forms.

But the electronic portal was not fully functional. GSTR-2A, which auto-populates ITC from suppliers’ returns, was not operational until September 2018. This meant that for the first 14 months of GST, taxpayers like Bharti Airtel could not verify their ITC entitlement through the portal. They had to rely on their own records.

Bharti Airtel—a large telecom operator with a complex supply chain—filed its GSTR-3B returns for July, August, and September 2017. Because it could not see the ITC available in GSTR-2A, it paid its entire output tax liability (OTL) in cash. A conservative approach. Better to overpay than risk a shortfall and penalties.

When GSTR-2A became operational in September 2018, Bharti Airtel’s tax team ran the reconciliation. The result was staggering: the company had overpaid approximately Rs.923 crores in cash. It had missed claiming ITC that was legitimately available from its suppliers.

The Circular That Blocked the Fix

Bharti Airtel moved to rectify its original GSTR-3B returns for July-September 2017. But it hit a wall. The government had issued Circular No. 26/26/2017-GST on December 29, 2017. Paragraph 4 of that circular stated that any omission or incorrect particulars discovered after filing GSTR-3B could only be rectified in the return for the month or quarter during which the error was noticed—not in the original return period.

In other words, if you overpaid in July 2017 and discovered the error in September 2018, you could only adjust the overpayment in your September 2018 return. You could not go back and correct the July 2017 return itself. This created a practical problem: the ITC that should have been claimed in July 2017 would now be claimed in September 2018, potentially affecting interest calculations, cash flow, and compliance with the time limits for ITC claims under Section 16 of the CGST Act.

Bharti Airtel challenged this restriction before the High Court of Delhi. The company argued that the circular was contrary to the CGST Act itself. Section 39(9) of the CGST Act, it said, allows a registered person to rectify any omission or incorrect particulars in a return. The only condition: rectification must be made before the due date for furnishing the return for the month or quarter in which the error is discovered. The circular, by restricting rectification to subsequent months only, was reading a limitation into the statute that did not exist.

The Delhi High Court’s Reading Down

On May 31, 2018, the Delhi High Court allowed Bharti Airtel’s writ petition. The court read down Paragraph 4 of the circular, holding that it was contrary to the provisions of the CGST Act. The court permitted Bharti Airtel to rectify its GSTR-3B returns for July-September 2017 to claim the ITC it had missed.

The High Court’s reasoning was straightforward: the circular could not override the statute. Section 39(9) of the CGST Act provides a mechanism for rectification. The circular, by restricting that mechanism, was ultra vires the Act. The court also noted that the portal’s non-functionality was a government failure, and the taxpayer should not suffer for it.

The Union of India appealed to the Supreme Court. The government argued that the self-assessment obligation under Section 59 of the CGST Act required the taxpayer to correctly assess its tax liability at the time of filing. The rectification mechanism under Section 39(9), the government said, was not intended to allow a taxpayer to go back and change a return after the fact. The circular, it argued, was merely a clarification of the law—not a new restriction.

The Supreme Court’s Framework: Self-Assessment and the Portal

The Supreme Court, in a judgment authored by Justice A.M. Khanwilkar, examined the interplay between the taxpayer’s self-assessment obligation and the functionality of the electronic portal. The Court laid down three key principles.

First, self-assessment is independent of portal functionality. The Court held that a registered person’s obligation to self-assess output tax liability and ITC under the CGST Act is based on records maintained by the taxpayer, not on the functionality of the common electronic portal. The portal is a facility, not the source of the right to ITC. The right to ITC flows from the statute and the taxpayer’s own records.

Second, Section 39(9) governs the rectification mechanism. The Court interpreted Section 39(9) to mean that rectification of omissions or incorrect particulars must be made in the return for the month or quarter during which such errors are noticed. This means the taxpayer cannot go back and change the original return for the error period. Instead, the correction must be made in the return for the period when the error is discovered.

Third, the electronic portal is a facilitator, not a source of right. The Court emphasized that the common electronic portal, including auto-populated forms like GSTR-2A, is an enabler. It does not create or extinguish substantive rights. The right to ITC exists independently of the portal. If the portal is non-functional, the taxpayer must rely on its own records to determine ITC entitlement.

These principles, taken together, suggest that the Delhi High Court’s reading down of the circular may have been too broad. The Supreme Court’s interpretation of Section 39(9) appears to align with the government’s position: rectification must be in the return for the period when the error is noticed, not in the original return period.

However, the judgment is truncated—the final operative order is not available in the provided text. The Supreme Court’s appeal by the Union of India against the Delhi High Court’s order was heard, but the outcome is not stated. This leaves practitioners in a state of uncertainty.

What This Means for Taxpayers and Practitioners

For advocates, CFOs, and founders, this case offers several practical lessons.

First, the GST portal is not your safety net. The Supreme Court has made it clear: the taxpayer’s obligation to self-assess is independent of the portal’s functionality. If the portal is down or forms are not operational, you cannot rely on that as an excuse for incorrect returns. You must maintain your own records and make your own assessments.

Second, rectification is prospective, not retrospective. Under Section 39(9), if you discover an error in a previous return, you cannot go back and change that return. You must correct the error in the return for the period when you discovered it. Timing matters. If you discover an error in September 2018, you must rectify it in your September 2018 return—not in your July 2017 return.

Third, government circulars can be challenged, but the statute is the final word. The Delhi High Court read down the circular because it was contrary to the CGST Act. But the Supreme Court’s interpretation of Section 39(9) suggests that the circular may have been consistent with the statute after all. The lesson: always check the statutory provision, not just the circular.

THE PLAY: When the GST portal is non-functional, maintain your own ITC records and file returns based on those records. If you discover an error later, rectify it in the return for the period of discovery—not the original error period. Do not rely on the portal to save you from self-assessment obligations.

The Bottom Line

Bharti Airtel’s overpayment was a direct result of a government portal that was not ready for the GST launch. The company did what any reasonable taxpayer would do: it paid in cash to avoid penalties. When it tried to fix the error, it was blocked by a circular that the Delhi High Court found to be contrary to the statute. The Supreme Court’s judgment, while truncated, clarifies that the taxpayer’s self-assessment obligation is independent of the portal, and rectification under Section 39(9) must be in the return for the period of discovery. For every taxpayer filing GST returns, the message is clear: your records, not the portal, are your best defense.