In general, expenses incurred in the ordinary course of business (to obtain, collect, and maintain taxable income) are deductible, subject to the requirements for documentary support.
Note that expenses relating to gross income subject to final income tax are not deductible for CIT purposes.
Depreciation, amortisation, and depletion
Depreciable/amortisable assets include both tangible and intangible property or costs, including the cost of extending building use rights, rights for business use, rights for use, and goodwill, with a useful life of more than one year, except land that is owned and used in business. Depreciation and amortisation may be calculated under the straight-line method or the declining-balance method on an individual asset basis. Once a method is chosen, it should be applied consistently. In calculating depreciation, depreciable assets are divided into the following classes:
|Class||Depreciation/amortisation rate (%)|
|Straight-line method||Declining-balance method|
|Useful life of 4 years||25||50|
|Useful life of 8 years||12.5||25|
|Useful life of 16 years||6.25||12.5|
|Useful life of 20 years||5||10|
Special rules apply for assets used in certain business fields and/or certain areas. Tax depreciation need not conform to book depreciation.
The costs incurred for acquiring rights, with a beneficial life of more than one year, for mining, oil, and natural gas concessions; forest concessions; and other rights to exploit natural resources should be amortised by the production-unit method. Except for the right to acquire oil and natural gas concessions, the depletion rate used should not exceed 20% per annum.
Organisational and start-up expenses
The costs of incorporation and expansion of the capital of an enterprise are claimed in full in the year in which the expenditure is incurred or are amortised using either the declining-balance or straight-line method at the above rates.
Costs incurred before the commencement of commercial operations with a useful life of longer than one year are capitalised and amortised according to the above rates.
Interest incurred in the ordinary course of business is deductible as long as the related loan is used for business purposes.
Interest on loans relating to time deposits (which income is subject to a final tax) is not deductible.
Interest on loans used to buy shares where dividends to be received are not subject to income tax is also not deductible.
A debt-to-equity ratio of 4:1 is generally applicable, which means that the amount of debt allowable in order to obtain full deductibility of the financing cost is limited to four times the equity amount. Exemption applies to certain taxpayers.
Uncollectible debts are deductible for tax purposes, with the following conditions:
- The creditor has recognised the amount of uncollectible receivables as expenses in the commercial income statement.
- The taxpayer must submit a list of uncollectible account receivables to the Directorate General of Tax.
- A legal case to enforce collection has been brought to a District Court or government agency that handles state receivables, there is a written agreement on cancellation of receivables/debt release and discharge between the concerned creditor and debtor, it has been publicised in a general or a special publication, or the debtor has otherwise acknowledged that one’s debts have been cancelled.
Donations for national disasters, education facilities, sport development, and social infrastructures, with certain conditions, may be deductible in the fiscal year when the donations are provided.
Benefits in kind
Most benefits received in kind by employees, such as free housing, are not tax-deductible to the entity providing the benefit. Free motor vehicle and telephone expenses, including depreciation, are tax-deductible but only for 50% of the total expenses incurred. Expenses for meals and transportation made available to all staff are tax-deductible. Apart from these, certain benefits in kind (e.g. housing provided in remote areas as designated by the MoF, Integrated Economic Development Zones as designated by Presidential Decree) can also be claimed as tax-deductible expenses.
Fines and penalties
Fines, penalties, and interest on underpayment of taxes are not deductible.
Land and buildings tax and regional taxes may be deducted from taxable income. With several exceptions, input VAT is also deductible against taxable income as long as it is not claimed as a credit against output VAT.
Net operating losses
Losses may be carried forward for a maximum period of five years. Carrying back of losses is not permitted. Offsetting losses within a corporate group is not permitted.
Payments to foreign affiliates
WHT is applied as a final tax on the recipient for payments of royalties, interest, and service fees to foreign non-resident companies. Excessive and non-arm’s-length payments to related parties are disallowed as deductions. The tax law denies deductions for all payments from a branch to its head office for royalties, interest, and services provided by the head office (exceptions apply for loans between bank branches and their head offices).