Error Analysis

Top 5 Common Pension Miscalculations

An error in your pension calculation could cost you thousands in retirement. Here are the most common mistakes we find and their potential impact.

Last updated: March 2026 • 10 minute read
25%
Of pension records contain errors
£12,000+
Average error value discovered
5+
Most common error types

Public sector pension schemes are complex, and with millions of members and decades of data, errors are surprisingly common. Our analysis of thousands of statements has revealed several recurring issues that cost members significant amounts in retirement.

The Most Common Errors We Find

1

McCloud Remedy Miscalculations

This is currently the single biggest source of errors. The remedy requires administrators to calculate seven years of pension benefits under two different sets of rules (legacy and reformed) and give the member the better outcome.

The Problem:

  • • Massive administrative task affecting millions
  • • Errors in identifying eligible members
  • • Difficulty sourcing historical data
  • • Incorrect calculation factors applied
  • • Complex scheme-specific implementation

The Impact:

An incorrect McCloud calculation can alter a member's lifetime pension value by thousands, or even tens of thousands, of pounds.

Note: McCloud affects service between April 2015 and March 2022 for eligible members. If you were in a public sector scheme before 2012 and had service during this period, you should see McCloud calculations on your statement.

2

Part-Time Service Errors

For members who have worked part-time, calculating pensionable service is more complex than for full-time staff. Small errors here compound over many years.

Common Issues:

  • • Incorrect Full-Time Equivalent (FTE) percentages
  • • Failure to account for hour changes
  • • Term-time only contracts calculated wrong
  • • Variable shift patterns (NHS staff)
  • • Job-share arrangements miscalculated

Real Example:

Teacher worked 0.8 FTE for 15 years

Recorded as 0.6 FTE = 3 years lost service

Impact: £3,000+ per year pension reduction

3

Missing Service or Allowances

Your total pensionable service is the foundation of your pension. Gaps or omissions in your record can be very costly, and every missing year is a year of lost pension accrual.

Often Missing:

  • • Short-term contracts and locum work
  • • Bank/agency work periods
  • • Service before system changes
  • • Cross-department transfers
  • • Pensionable allowances (Police/Fire)

High-Risk Groups:

  • • NHS bank/locum staff
  • • Police officers with special allowances
  • • Teachers with multiple schools
  • • Civil servants who changed departments
  • • Long-serving employees (20+ years)
4

Incorrect Transfer-In Calculations

Many public sector workers move between different schemes during their careers (e.g., from local government to the NHS). When service is transferred, complex calculations determine the "service credit" you receive.

Why Errors Occur:

  • • Complex actuarial calculations required
  • • Different scheme rules and factors
  • • Historical data quality issues
  • • Time-dependent calculation factors
  • • Manual processing of transfers

Impact Assessment:

High impact potential: This can lead to a significant part of your career being undervalued in your final pension calculation, potentially affecting 10+ years of service value.

5

Career Break Errors

Periods of leave such as maternity, paternity, or adoption leave are protected and should count towards your pension as if you were still at work. However, these are often incorrectly recorded.

Protected Leave Types:

  • • Maternity leave (including unpaid extension)
  • • Paternity and adoption leave
  • • Some types of sick leave
  • • Career break schemes
  • • Trade union duties (sometimes)

Common Errors:

  • • Leave recorded as "unpaid gap"
  • • Wrong salary used for pension calculations
  • • Additional maternity leave rules applied incorrectly
  • • Career breaks treated as opted out
  • • Inconsistent application of protection rules

Key principle: Protected leave should not create "gaps" in your service record or reduce your final pension. If you see career breaks reducing your pension entitlement, this needs investigation.

What These Errors Cost

Financial Impact Examples

Small Annual Error:

£500 per year pension understatement

Over 20-year retirement: £10,000+ lost

Significant Error:

£2,000 per year pension understatement

Over 20-year retirement: £40,000+ lost

These figures don't include inflation increases or survivor benefits. The true cost of pension errors compounds over time.

The Hidden Cost

Many pension errors go undetected until retirement, when it's often too late to correct them easily. Early detection through regular pension checking is crucial for protecting your retirement income.

Don't Let Errors Cost You Thousands

Professional pension checking can identify these errors before they impact your retirement. Many providers offer "no error, no fee" arrangements.