ACCA PM Variance Analysis: 5 Mistakes Costing You Marks in 2026

The mistakes examiners keep flagging

PM has a 40% pass rate. Variance analysis appears in almost every sitting. If you’re making any of these five mistakes, you’re handing marks away — and you probably don’t even know it.

The December 2025 examiner report made it clear: candidates who lose marks on variance analysis aren’t failing because they can’t calculate. They’re failing because they keep repeating the same avoidable errors. Here’s what to fix before your next sitting.

1. Using revenue or profit instead of contribution

This is the single most damaging mistake in PM variance questions. When you calculate a sales volume variance, you must use standard contribution per unit — not revenue, not profit. PM operates under marginal costing. Using the wrong metric doesn’t just lose you the calculation mark — it often flips the direction of the variance entirely, which then wrecks your discussion.

Wrong: Sales volume variance = (Actual units – Budgeted units) × Standard selling price per unit

Right: Sales volume variance = (Actual units – Budgeted units) × Standard contribution per unit

If a product sells for £50 with variable costs of £30, the standard contribution is £20. Selling 200 extra units gives a £4,000 favourable volume variance — not £10,000. Get this wrong and everything downstream falls apart.

2. Not labelling variances as Favourable or Adverse

Every single variance needs an explicit F or A label. No exceptions. Writing “£4,000” without stating whether it’s favourable or adverse means the examiner cannot award the mark — even if your calculation is correct. This costs candidates more easy marks than almost any other error.

The fix is simple: make it a habit. After every variance you calculate, write F or A. If actual cost is below standard cost, it’s favourable. If actual revenue or contribution exceeds standard, it’s favourable. Drill this until it’s automatic.

3. Flexing to the wrong base

Variance analysis compares actual results to a flexed budget — the budget adjusted for actual activity levels. Too many candidates compare actual results against the original (fixed) budget instead. That tells you nothing useful about performance; it just shows that volume was different from plan.

The whole point of flexing is to isolate controllable performance from volume effects. If the question gives you a budget for 10,000 units but actual production was 12,000, your standard costs must be based on 12,000 units. Compare like with like.

4. Not reconciling sub-variances

If a question asks you to calculate material price and usage variances, your two figures should reconcile back to the total material cost variance. If they don’t, something is wrong — and you’ll know to check your workings before moving on.

Same applies to sales: mix + quantity = total volume variance. Labour: rate + efficiency = total labour variance. Build this check into every answer. It takes 30 seconds and catches errors that would otherwise cost you 4-6 marks.

5. Writing generic discussion points

The examiner report for March 2024 noted that candidates averaged just 3.2 out of 9 on discussion marks. That’s a huge gap — and it’s because students write things like “the variance is adverse which means costs were higher than expected.” That earns nothing.

What earns marks: linking variances to the scenario. “The adverse material usage variance of £2,400 may be caused by the switch to cheaper supplier noted in the scenario, which would also explain the favourable price variance of £1,800 — suggesting the net cost of the quality trade-off was £600 adverse.” That’s one sentence, and it demonstrates the interrelationship between variances that examiners are specifically looking for.

What to do now

1. Practise with contribution, not profit. Go to the aCOWtancy PM Exam Centre and attempt every past question involving sales variances. Check you’re using standard contribution per unit every single time.

2. Build reconciliation into your method. Before writing any discussion, add up your sub-variances and prove they equal the total. This is your error-catching safety net and examiners love to see it.

3. Write discussion points that link variances together. For every adverse variance, ask yourself: “Is there a favourable variance elsewhere that explains this?” If a question mentions a scenario detail — a new supplier, a machine breakdown, overtime working — connect it to a specific variance.

PM’s pass rate dropped to 40% in December 2025 — the lowest since September 2021. Variance analysis isn’t going away. But with these five fixes, you’re already ahead of the majority of candidates who keep making the same mistakes every sitting.