MAT or Minimum Alternate Tax was introduced in 1987 to collect taxes from zero tax companies. It levies a tax rate of 15% on the book profits of companies to bring them in the tax net. Companies can claim MAT credit for taxes paid over their normal tax liability which can be carried forward for 15 years. All companies, including those in Special Economic Zones, are required to pay MAT and file MAT reports. The introduction of MAT helps reduce tax evasion and ensures that companies pay a minimum level of tax.