Taxation (UK) · Principal sources of revenue law and practice

Tax Avoidance, Tax Evasion and the GAAR Explained

Updated 11 October 2026 · Fact-checked

Tax planning uses reliefs as Parliament intended. Tax avoidance follows the letter of the law but defeats its purpose. Tax evasion is illegal: hiding income or lying to HMRC. The General Anti-Abuse Rule (GAAR) lets HMRC counteract abusive arrangements, so the tax advantage is removed.

Understand Tax Avoidance, Tax Evasion and the GAAR

Every taxpayer may arrange their affairs to pay less tax. The question is how. There are three levels, and the exam asks you to tell them apart.

Tax planning (mitigation) means using reliefs, allowances and exemptions in the way Parliament meant. Examples: using your ISA allowance, making pension contributions, or transferring assets between spouses to use two annual exempt amounts. It is legal and acceptable.

Tax avoidance means arranging affairs to get a tax advantage that Parliament did not intend. The arrangement may comply with the wording of the law, but it defeats the purpose. It is not a crime, but HMRC can challenge it and counter it. Typical signs are artificial steps, circular transactions and no commercial purpose other than saving tax.

Tax evasion means deliberately giving HMRC false information or hiding information to pay less tax. Examples: not declaring income, claiming expenses that were never incurred, or inflating costs. It is a criminal offence and can lead to penalties, prosecution and a prison sentence.

The General Anti-Abuse Rule (GAAR) is a statutory rule aimed at abusive tax avoidance. An arrangement is caught if its main purpose, or one of its main purposes, is to obtain a tax advantage and it cannot reasonably be regarded as a reasonable course of action. If the GAAR applies, HMRC makes just and reasonable adjustments to counteract the tax advantage. Before HMRC acts, an independent advisory panel gives an opinion. The courts also take account of that opinion.

Other measures sit alongside the GAAR. Targeted anti-avoidance rules (TAARs) are built into specific legislation. Disclosure rules require promoters of certain schemes to tell HMRC about them. Case law, such as the approach of looking at the real commercial substance of a transaction, also limits avoidance. Your notes on the sources of UK tax law cover this.

Key rules to remember

Tax planning (mitigation): Legal + uses reliefs as intended by Parliament; Acceptable. Examples: ISAs, pension contributions, spouse transfers.
Tax avoidance: Legal in wording + defeats the intention of the law; Not a crime, but HMRC can counteract it. Often artificial, with no commercial purpose.
Tax evasion: Illegal + deliberate dishonesty towards HMRC; Criminal offence. Hiding income or falsifying claims.
GAAR test: Tax advantage + main purpose (or one of the main purposes) + not a reasonable course of action = abusive; If met, HMRC makes just and reasonable adjustments to counteract the advantage.
GAAR safeguard: Independent advisory panel opinion before HMRC counteracts; A procedural safeguard, so HMRC cannot act on the GAAR alone.

How to solve Tax Avoidance, Tax Evasion and the GAAR questions

Use this method for any question asking you to classify an arrangement or explain the anti-avoidance rules.

1Read the facts and list exactly what the taxpayer did.
2Ask whether anything was hidden, false or undeclared. If yes, it is evasion.
3If everything was disclosed, ask whether the taxpayer used a relief as Parliament intended. If yes, it is acceptable tax planning.
4If the wording is met but the arrangement is artificial, circular or has no commercial purpose beyond the tax saving, classify it as avoidance.
5If avoidance is likely abusive, apply the GAAR test: tax advantage, main purpose, and not a reasonable course of action.
6State the consequence: evasion means penalties and possible prosecution; GAAR means counteraction by just and reasonable adjustments.
7Give a reason for each point and keep to what the question asks for.

Quickest way: Hidden, intended or artificial?

When to use it: Use this for objective test questions asking you to label a scenario.

Hidden or false information to HMRC: evasion.
Open and as Parliament intended: planning.
Open but artificial, with the tax saving as the point: avoidance, possibly caught by the GAAR.
Check the wording: 'deliberately' and 'dishonestly' point to evasion.

Common mistakes in Tax Avoidance, Tax Evasion and the GAAR

Saying tax avoidance is illegal.
The word sounds like evasion and both reduce tax.
Fix: Avoidance is legal in form but can be counteracted. Only evasion is a crime.
Treating all tax planning as avoidance.
Students think any attempt to reduce tax is suspect.
Fix: Using ISAs, pensions and allowances as intended is acceptable planning.
Describing the GAAR as applying to any tax saving.
The rule is remembered as an 'anti-abuse' rule without its conditions.
Fix: State the conditions: a tax advantage, a main purpose test, and an arrangement that is not a reasonable course of action.
Forgetting the consequence of the GAAR.
Students describe the rule but stop before the outcome.
Fix: Say HMRC makes just and reasonable adjustments to counteract the tax advantage, after an advisory panel opinion.
Calling an honest error evasion.
Both lead to underpaid tax.
Fix: Evasion needs deliberate dishonesty. An innocent mistake is an error, dealt with by penalties for errors.

Worked examples

Example 1

Anna runs a business. She leaves £20,000 of cash takings out of her records and does not declare them on her tax return. Her friend Ben gives shares to his wife so that her unused annual exempt amount can be used when the shares are sold. Classify each and explain.

Show the solution

Anna: the takings were deliberately hidden from HMRC and the return is false.
This is tax evasion, a criminal offence, so penalties and prosecution are possible.
Ben: the transfer is open and uses an annual exempt amount as Parliament intended.
This is acceptable tax planning, not avoidance.

Answer: Anna's conduct is tax evasion (illegal). Ben's is legitimate tax planning.

Example 2

A company enters a series of circular transactions with no commercial purpose. They create a tax advantage by technically meeting the wording of a relief. Explain whether the GAAR may apply and what HMRC can do.

Show the solution

The arrangement is open and follows the wording, so it is not evasion. Its artificial nature points to avoidance.
GAAR test: it produces a tax advantage.
Obtaining the advantage is the main purpose, or one of the main purposes.
Circular steps with no commercial purpose cannot reasonably be regarded as a reasonable course of action.
So the arrangement is abusive and the GAAR can apply.
Before acting, HMRC refers the case to the independent advisory panel and takes its opinion into account.
HMRC then makes just and reasonable adjustments to counteract the tax advantage.

Answer: The GAAR may apply because the arrangement is abusive. HMRC, after the advisory panel's opinion, can counteract the tax advantage by just and reasonable adjustments.

Exam tips

Define all three terms in one line each. Marks are often for the distinction.
Use the word 'deliberate' for evasion and 'artificial' or 'against the intention of Parliament' for avoidance.
When asked about the GAAR, give the three conditions and then the consequence.
In planning questions, recommend only legitimate planning and say that evasion is never acceptable.
Objective test questions are all or nothing, so check the classification wording carefully.

Practice questions from Principal sources of revenue law and practice

Tax Avoidance, Tax Evasion and the GAAR in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Tax Avoidance, Tax Evasion and the GAAR: frequently asked questions

What is the difference between tax avoidance and tax evasion?

Avoidance reduces tax by arrangements that follow the wording of the law but defeat its purpose. It is not a crime, though HMRC can counter it. Evasion is deliberately hiding or misstating information to pay less tax and is a criminal offence.

What is the GAAR in simple terms?

It is a rule that lets HMRC counteract abusive tax avoidance. The arrangement must give a tax advantage, have obtaining it as a main purpose, and not be a reasonable course of action. HMRC then makes just and reasonable adjustments.

Does HMRC need approval before applying the GAAR?

HMRC must refer the matter to an independent advisory panel and take its opinion into account before counteracting the advantage. This is a safeguard for taxpayers.

Is tax planning allowed?

Yes. Using reliefs, allowances and exemptions as Parliament intended, such as ISAs or pension contributions, is legitimate planning.