ACCA FM Investment Appraisal: NPV Mistakes & Examiner Evidence

ACCA FM Investment Appraisal

Investment appraisal accounts for 20–25% of ACCA FM marks every sitting. Yet the SD24 and MJ25 examiner reports reveal the same NPV errors appearing repeatedly — sunk costs included, working capital mistreated, IRR interpolation botched. This guide maps every mistake the examiner flags to the exact technique you need, with real exam evidence from Galle Co (SD24) and Sulu Co (MJ25).

Table of Contents

1. NPV Calculations: 7 Mistakes the Examiner Keeps Flagging

The SD24 examiner report on Galle Co and the MJ25 report on Sulu Co identify the same recurring errors. The FM pass rate dropped to 48% in December 2025 — most marks are lost on detail inside NPV calculations, not on missing formulas.

Mistake 1: Including Sunk Costs

Examiner evidence (MJ25, Sulu Co): R&D costs of $200,000 already spent were classified as sunk costs. Candidates incorrectly included the annual $50,000 amortisation in cash flows. The correct approach: add back the $50,000 to convert from profit to cash flow.

Sunk costs are past expenditures that cannot be recovered regardless of whether the project proceeds. They must be excluded from investment appraisal calculations entirely.

Mistake 2: Using Profit Instead of Cash Flows

Examiner evidence (SD24, Galle Co): Too many candidates failed to convert from profit to cash flow — they either skipped adjustments or deducted depreciation twice (once as expense, then again as adjustment).

The rule: add back depreciation and non-cash items, then handle working capital changes separately. If the question provides revenue and cost figures directly, you are already working with cash flows.

Mistake 3: Tax Timing Errors

Examiner guidance: Recent papers state explicitly that tax is paid at the end of the year to which it relates. Candidates who automatically defer tax by one year lose marks when the question says otherwise.

Always read the question requirement for specific tax timing. Apply the correct tax rate to taxable cash flows at the specified timing point.

Mistake 4: Working Capital — Total vs Incremental

Examiner evidence (SD24 & MJ25): Working capital is one of the most reliable mark-losers in FM. Two errors dominate: using total working capital each year instead of the incremental change, and failing to release working capital in the final year.

Mistake 5: Residual Values & Balancing Allowances

When equipment is sold at a value different from its tax-written-down value (TWDV), candidates must calculate the balancing allowance or charge. The examiner reports candidates frequently skip this step entirely.

• Balancing allowance = TWDV − Sale proceeds (when TWDV > proceeds) — gives tax relief
• Balancing charge = Sale proceeds − TWDV (when proceeds > TWDV) — creates tax liability

Understanding capital structure implications helps when residual values affect post-project gearing ratios.

Mistake 6: Spreadsheet NPV Function Errors

Examiner evidence: The FM examiner has recommended using the spreadsheet NPV function rather than tabular discount factors. However, candidates incorrectly include Year 0 in the NPV function.

Correct syntax: =NPV(rate, Year1:YearN) + Year0_cashflow

The NPV function assumes the first value occurs at T1, not T0. Including the initial investment inside the function discounts it by one year, understating the outflow.

Mistake 7: Market Value vs Book Value

Examiner evidence (SD24): Candidates used book values for equity when calculating post-project gearing. The correct approach: calculate new EPS, apply the unchanged P/E ratio to find the new share price, then use market values for gearing calculations.

2. Capital Rationing: Sulu Co MJ25 Walkthrough

Examiner evidence (MJ25, Sulu Co): This question tested divisible capital rationing with $2.1m available and mutually exclusive projects. The examiner noted candidates must rank by profitability index (PI), not by NPV alone.

Divisible Projects: Profitability Index Method

The MJ25 examiner report states that Project C should be rejected immediately due to its negative NPV. The optimal plan: 100% of D ($950k), 100% of B ($850k), 50% of E ($300k), achieving total NPV of $857.5k.

Hard vs Soft Capital Rationing

Hard rationing stems from external constraints: bank lending restrictions, lack of collateral, high gearing concerns, or tight economic conditions. Soft rationing arises internally: management growth-rate policies, dividend commitments, or strategic risk limits.

Effective working capital management often determines how much internal funding is available before capital rationing bites.

3. Real vs Nominal: Inflation Adjustments

The examiner frequently tests whether candidates can apply inflation correctly. Confusion between real and nominal approaches costs marks every sitting.

The Fisher Formula

(1 + nominal rate) = (1 + real rate) × (1 + inflation rate)

Example: Real cost of capital 4.8%, general inflation 5.0%. Nominal cost of capital = (1.048 × 1.05) − 1 = 10.04%.

Nominal Approach (Most Common in Exams)

1. Inflate revenues and costs at their specific inflation rates
2. Use general inflation only when no specific rate is given
3. Discount at the nominal cost of capital

Cumulative inflation example: Year 1 price = $70 × 1.045 = $73.15. Year 2 = $70 × (1.045)² = $76.44.

Critical Tax Point in Inflation

Tax-allowable depreciation does not inflate. This is the single most-tested nuance. TAD benefits remain at their nominal (historical cost) values regardless of inflation — creating a relative disadvantage in high-inflation environments. In a real-terms NPV, you must still include TAD at nominal values.

Students preparing for risk management questions should understand how inflation uncertainty compounds project risk.

4. IRR vs NPV: When Each Method Applies

The examiner expects candidates to know why NPV is the primary method, not just how to calculate it.

NPV Advantages Over IRR

IRR Interpolation: Getting It Right

Examiner evidence (SD24 & MJ25): Candidates mix up which NPV goes where in the formula, or use two positive (or two negative) NPVs instead of one of each.

IRR = a + [NPV_a ÷ (NPV_a − NPV_b)] × (b − a)

Where: a = lower rate (positive NPV), b = higher rate (negative NPV).

Example: NPV at 7% = +$35,000. NPV at 11% = −$25,000. IRR = 7% + [35,000 ÷ (35,000 − (−25,000))] × (11% − 7%) = 7% + [35,000 ÷ 60,000] × 4% = 9.3%.

Common error: writing 35,000 ÷ (35,000 − 25,000) = wrong! The denominator must account for the sign difference.

For advanced valuation techniques using IRR, see our dedicated guide.

5. Sensitivity Analysis: Quick Marks Available

Sensitivity analysis regularly appears for 2–3 marks. The formula is straightforward, but candidates lose marks by not interpreting the result.

Sensitivity = (NPV ÷ PV of the variable being tested) × 100%

Example: NPV = $247k, PV of sales revenue = $1.2m. Sensitivity = 20.6%. Meaning: sales volume would need to fall by 20.6% before the project becomes unviable.

Limitations the Examiner Expects You to State

• Tests variables in isolation — ignores correlation between variables
• Provides no probability of the change occurring
• Assumes linear relationships that may not hold
• Does not indicate which scenario is most likely

For a broader perspective on handling uncertainty in FM, see our exam tips guide covering all sections.

6. Tax-Allowable Depreciation in NPV

TAD questions appear in most Section C investment appraisal questions. The calculation itself is mechanical, but timing errors are common.

25% Reducing Balance (Most Common)

*Assuming sale proceeds of $100,000. Balancing allowance = $210,937 − $100,000 = $110,937.

When tax is paid one year in arrears, the Year 1 TAD benefit becomes a Year 2 cash inflow. Always verify the question’s specific timing instruction.

For comprehensive study materials covering TAD calculations, consider BPP FM printed books or BPP ECR online classes.

7. Spreadsheet Layout & Exam Technique

Examiner evidence: The examiner consistently emphasises clear workings, structured layouts, and commenting on results — not just calculating numbers.

Recommended NPV Layout

Use a columnar format with years across the top (T0 to T4/T5). Rows should follow this order: revenue, variable costs, fixed costs, taxable cash flow, tax, after-tax cash flow, add back depreciation, TAD benefit, capital expenditure, working capital, net cash flow, discount factor, present value.

Time Management

Examiner’s Recurring Advice

• Show workings clearly — method marks protect you even when arithmetic slips
• Comment on results — stating "NPV is positive, accept the project" earns the advisory mark
• Read the requirement — the SD24 report notes candidates answering questions that were not asked (defining risk vs uncertainty when it was not required)
• Use the formula sheet — provided in the exam; no need to memorise annuity or perpetuity formulas

For the complete list of FM technical articles from ACCA, see our FM technical articles compilation.

FAQ: ACCA FM Investment Appraisal

For official ACCA FM exam guidance, syllabus updates, and practice questions, visit the ACCA FM resource page.Also refer our detailed guide on tips on how to pass the ACCA FM Exams.