Principles of Taxation
This domain tests whether you can explain why taxes exist, how the UK tax system is structured and administered, how taxes are classified, and how a simple liability is computed. Expect short definitions, classification questions, administration and penalty rules, and computations that reward shown reasoning.
Purpose and design of taxes
Taxes raise revenue for public services, redistribute income and wealth, correct externalities (for example, duties on tobacco and alcohol), and shape behaviour through reliefs and incentives. Adam Smith's canons remain a useful checklist: equity (fairness between taxpayers), certainty (the taxpayer knows the liability), convenience (timing and method of payment suit the payer) and economy (collection cost is low relative to yield).
Classify every tax you meet:
- Direct vs indirect - income tax and corporation tax are direct (assessed on the person); VAT and excise duties are indirect (collected by traders from consumers).
- Progressive, proportional, regressive - income tax with rising bands is progressive; a single flat rate is proportional; a fixed charge such as a flat annual fee falls hardest, proportionally, on low income.
- Base vs rate - identify what is taxed (income, profits, gains, consumption) before applying rates and allowances.
Administration in the UK
Policy is set by HM Treasury and legislated annually in the Finance Act; HMRC administers and collects. Most individuals and many businesses use self assessment: register, submit a return, and pay. Online filing and balancing payment fall on 31 January following the tax year, with payments on account on 31 January and 31 July. Late filing and late payment attract escalating fixed penalties plus interest. Disputed decisions can be appealed, ultimately to the tax tribunals.
Worked example
Assume taxable income of £50,000, a personal allowance of £12,570, a 20% basic rate on the first £37,700 of taxable income and 40% above.
- Taxable income = £50,000 − £12,570 = £37,430.
- All of it falls in the basic-rate band, so tax = £37,430 × 20% = £7,486. Reasoning: always deduct allowable reliefs before applying banded rates, and check whether the allowance is tapered (it reduces above £100,000).
Traps that cost marks
Mixing marginal and average rates; calling VAT direct; describing tax avoidance (legal) as evasion (illegal); applying the higher rate before exhausting the basic band; forgetting that Scottish and Welsh rates affect only certain income types; and ignoring interest when stating penalties.