Thin capitalization refers to a situation where a company is financed through high levels of debt compared to equity, resulting in a thin capital structure. Section 94B of the Indian Income Tax Act governs thin capitalization by restricting the deduction of interest expenses in cases where debt is from an associated enterprise or guaranteed by an associated enterprise. Excess interest, defined as interest exceeding 30% of EBITDA or total interest paid to associated enterprises, whichever is lower, is not deductible and can be carried forward for up to 8 years. The provisions apply to both debt from non-resident associated enterprises and debt from Indian lenders that is guaranteed by a non-resident associated enterprise.