The Union Budget 2026 has put a countdown on one of the most significant tax assets on many corporate balance sheets: MAT credit. While Minimum Alternate Tax (MAT) was originally designed to ensure a floor level of tax for companies using heavy deductions, it is now being utilized as a tool to urge a shift toward the simplified new tax regime.

The proposed amendments create a clear fork in the road for domestic companies:

• Staying in the Old Regime: You benefit from a slightly lower MAT rate of 14%, but any MAT paid is a “final tax”. Crucially, you cannot use your old MAT credit while staying in the old regime.
• Moving to the New Regime from FY 26-27 or onwards: You unlock your accumulated MAT credit upto 31 March 2026, but you can only use it to offset up to 25% of your tax bill each year.

For foreign companies, the rules are more flexible, as the 25% utilization cap does not apply to them. However, for domestic firms, the “Effective Tax Rate” could drop as low as 18.88% if the transition is managed correctly.

No retrospective relief is provided for early adopters of the new tax regime, and any lapsed MAT credit will not be restored.

Why 31 March 2026 Is the Pivot Point

Companies staying in the old regime after 31 March 2026 cannot access existing MAT credit while doing so, and no new credit will be generated. The credit survives on paper for residual 15-year statutory period, but only becomes usable upon switching to the new regime. This transforms MAT credit from a passive balance sheet asset into a time-sensitive instrument.

The Way Forward

Under Union Budget 2026, the tax regime transition decision for domestic companies requires active modelling:

• Map year-wise MAT credit expiry
• Project tax trade-off between old and new regime
• Evaluate if 25% annual cap permits utilisation before the credit lapses
• Assess accounting impact on deferred tax

Well-modelled, timely decisions will separate companies that capture this transitional benefit from those that let it expire unused.