Deferred Tax Liability

Companies keep two sets of records: GAAP financials (for investors) and the tax return (for the IRS). When a timing difference makes book pre-tax income HIGHER than taxable income, the company reports a higher tax expense on its income statement than it actually pays in cash — the difference is parked on the balance sheet as a deferred tax liability. It's a real obligation because the timing difference will reverse in future periods, at which point taxable income exceeds book income and the company pays the catch-up.

For tax purposes, companies use accelerated methods (like MACRS / bonus depreciation in the U.S.), front-loading depreciation deductions. For book purposes, they typically use straight-line. In the early years, the tax deduction is larger, so taxable income (and cash taxes) are LOWER than book income suggests. That under-payment accumulates as a DTL. In later years, book depreciation exceeds tax depreciation, taxable income rises above book income, and the DTL reverses (shrinks) as the company pays the deferred tax.

DTLs are huge in deal accounting. In an asset purchase or a write-up of acquired assets, the buyer steps up asset values for BOOK purposes but often can't for TAX purposes (in a stock deal), creating extra book depreciation that isn't tax-deductible — this generates a DTL at close. On the cash flow statement, an INCREASE in a DTL is a source of cash (added back in operating activities), because book tax expense overstates the actual cash tax paid. A decreasing (reversing) DTL is a use of cash.