Office for National Statistics Wealth and Assets Survey - Pension Wealth Annuity Factors - Round 8 Guidance Note
Updated 26 June 2025
1. Introduction
Background
1.1 The Office for National Statistics (βONSβ) produce and publish a biennial survey of the wealth and assets of households in Great Britain (the βWASβ). We understand the WAS is used widely across government to inform policy making.
1.2 Pension wealth is captured alongside property, physical assets and net financial wealth (e.g. savings). Pension wealth is split across two categories: pensions that are defined contribution (βDCβ) in nature, and pensions that are defined benefit (βDBβ) in nature.
1.3 The ONS use a model (as set out in Appendix B) to estimate pension wealth based on answers to household survey questions. This model is subject to public scrutiny.
1.4 The ONS commissioned the Government Actuaryβs Department (βGADβ) to provide annuity factors for use in the ONSβs pension wealth model for Round 8 of the wealth and assets survey (i.e. interviews conducted between April 2020 and March 2022).
1.5 The annuity factors GAD have calculated for Round 8 are published in the spreadsheet titled βONS-WAS Round 8 Annuities.odsβ on the 25 June 2025, which represent the ππ π (π‘) variable in the ONS model (see Appendix B).
1.6 The assumptions used to calculate these annuities are set out in Appendix A. Please refer to GADβs report on the discount rate methodology titled βvaluing defined benefit pension wealthβ dated 5 December 2024, which includes further detail on the financial assumptions.
Purpose and third-party reliance
1.7 This guidance note is addressed to the Wealth and Pensions Analysis team within the ONS. This note shows how the annuity factors GAD have calculated should be used in the ONS wealth model to place an approximate value on the wealth of pension benefits.
1.8 This guidance note has been prepared for the use of the ONS for the purposes of demonstrating the application of the annuity factors in Round 8 only. It includes examples of how these annuity factors should be applied in practice for different situations and types of member.
1.9 Other than the ONS, no person or third party is entitled to place any reliance on the contents of this guidance, except to any extent explicitly stated herein. GAD has no liability to any person or third party for any action taken or for any failure to act, either in whole or in part, on the basis of this guidance, whether or not GAD has agreed to the disclosure of its advice to the third party.
Limitations
1.10 This guidance should not be used for any purpose other than those set out in this guidance.
1.11 ONS should ensure they are content that the assumptions used to calculate the annuity factors are reasonable for their purposes. The ONS need to ensure that they are using the appropriate factors when performing calculations, and applying the factors as intended.
1.12 Advice provided by GAD must be taken in context and is intended to be considered in its entirety. Individual sections, if considered in isolation, may be misleading, and conclusions reached by a review of some sections on their own may be incorrect. GAD does not accept responsibility for advice that is altered or used selectively. Clarification should be sought if there is any doubt about the intention or scope of advice provided by GAD.
Compliance
1.13 Other aspects of ONSβs model review, including a review of the questionnaire used to collect data for the model, are outside the scope of this guidance note.
1.14 This guidance note and annuity factors, and the work undertaken to produce it, has been carried out in accordance with the applicable Technical Actuarial Standards: TAS 100 issued by the Financial Reporting Council (FRC). The FRC sets technical standards for actuarial work in the UK.
2. Pension wealth conversion annuity factors
2.1 The annuity factors set out in the spreadsheet titled βONS-WAS Round 8 Annuities.odsβ have been calculated using the assumptions as set out in Appendix A.
2.2 These annuity factors are intended to be used in the ONSβs current wealth model as set out in Appendix B to approximate the overall wealth of DB pensions (and DC pensions in payment)(Note 1) for Round 8 of the ONSβs Wealth and Assets Survey.
2.3 The user will need to select the relevant factor for each individual pension from the relevant table (1-4), using the following identifiers (as established in the ONS Round 8 survey responses): Age (last birthday) Sex (male/female) Pensioner status (current pensioner, active or deferred member) Term to assumed retirement age (complete years for active or deferred members from their last birthday) Member pension or survivorβs pension (only for pensions already in payment)
2.4 The relevant factor table (1-4) to refer to in the spreadsheet are:
Category | Males | Females |
---|---|---|
Current pensioner | Table 1, column B. βMale pensionerβ | Table 2, column B. βFemale pensionerβ |
Survivor pensioner (receiving a dependant pension) | Table 1, column C. βMale survivorβ | Table 2, column C. βFemale survivorβ |
Active or deferred/retained (i.e. pension not in payment yet) | Table 3 (column depends on term to retirement age) | Table 4 (column depends on term to retirement age) |
2.5 For any non-pensioners who are over their retirement age, the user should refer to tables 3 or 4 (depending on male or female) and look up the relevant annuity factors assuming zero term to retirement at the memberβs age at the interview date. See example 5 in section 3 below.
Note 1: As per GAD recommendation 7 in Discount Rate methodology report
3. Example calculations
This section provides examples of the calculations to estimate the pension wealth for individuals, by applying the relevant annuity factor, ππ π (π‘), to the annual pension using the ONSβs model (as set out in appendix B).
For the non-pensioner examples, the calculations assume π = 2.40%, in line with the recommendation in GADβs advice βvaluing defined benefit pension wealthβ paper dated 5 December 2024.
Example 1: Current pensioner
Male age 70 years and 2 months at interview date
Annual pension in payment of Β£25,000 pa at interview date (ππ ππ πππ πππππ)
Table 1: Male pensioner annuity factor for a 70 year old: 14.84 (ππ π (π‘) ππ πππ πππππ)
Current pensioner, so no discounting factor required or lump sum payment.
Estimated pension wealth at interview date: Β£25,000 x 14.84 = Β£371,000
Example 2: Partner/survivor
Female, age 85 years and 9 months at interview date
Partnerβs annual pension in payment of Β£2,500 pa at interview date (ππ ππ πππ πππππ)
Table 2: Female survivor annuity factor for an 85 year old: 6.27 (ππ π (π‘) ππ πππ πππππ)
Current pensioner, so no discounting factor required or lump sum payment.
Estimated pension wealth at interview date: Β£2,500 x 6.27 = Β£15,675
Example 3: Active member (DB pension)
Male, age 40 years and 7 months at interview date
Estimated accrued DB pension of Β£15,000 pa at interview date (ππ ππ πππ πππππ)
Assumed retirement age in ONS model: 62
Years to assumed retirement age: 62 β 40.58 = 21.42 years
For term to retirement in the factor table, use rounded age at last birthday: 62 β 40 = 22
Table 3: Male annuity factor for a 40 year old with 22 years to retirement: 20.46 (ππ π (π‘) ππ πππ πππππ)
Estimated DB pension wealth at interview date: Β£15,000 x 20.46 / (1+2.40%) 22 = Β£182,137
Example 4: Deferred/retained member (DB pension)
Female, age 55 years and 6 months at interview date
Estimated accrued DB pension of Β£30,000 pa at interview date (ππ ππ πππ πππππ)
Assumed retirement age in ONS model: 65
Years to assumed retirement age: 65 β 55.5 = 9.5 years
For term to retirement in the factor table, use rounded age at last birthday: 65 β 55 = 10
Table 4: Female annuity factor for a 55 year old with 10 years to retirement: 18.56 (ππ π (π‘) ππ πππ πππππ)
Estimated DB pension wealth at interview date: Β£30,000 x 18.56 / (1+2.40%) 10 = Β£439,238
Example 5: Deferred member over normal retirement age (DB pension)
Male, age 72 years and 6 months at interview date
Estimated accrued DB pension of Β£35,000 pa at interview date (ππ ππ πππ πππππ)
Assumed retirement age in ONS model: 72.5
Years to assumed retirement age: 0 years (assume retires immediately)
Table 3: Male annuity factor for a 72 year old with 0 years to retirement: 13.91 (ππ π (π‘) ππ πππ πππππ)
Estimated DB pension wealth at interview date: Β£35,000 x 13.91 / (1+2.40%) 0 = Β£486,850
Appendix A: assumptions underlying the Round 8 annuity factors
A summary of the assumptions used to calculate the annuity factors is shown below:
Assumptions | Round 8 |
---|---|
Net discount rate | 2.40% |
Post-retirement mortality base tables (Note 1): | Μύ |
Male pensioner | 101% of S3PMA |
Female pensioner | 104% of S3PFA |
Male partner | 102% of S3DMA |
Female partner | 101% of S3DFA |
Future mortality improvements | ONS 2020 population projections |
Commutation of pension at retirement | Nil |
Marital assumptions: | Μύ |
Proportion married | ONS 2022 population estimates by marital status and living arrangements |
Age difference | Males 2 years older than eligible partner (and vice versa) |
Assumed partner pension proportion | 50% of original memberβs pension |
Gender of partner | Partners are assumed to be the opposite gender to the member |
Guarantee period for lump payment on death of member | Current pensioners: 0 years |
Μύ | Non-pensioners: 5 years |
The annuity factors assume no mortality before retirement age.
The factors do not include revaluation rates or assumed salary increases before retirement, as this is allowed for separately in the ONSβs model shown in Appendix B.
Note 1:
Appendix B: ONS model breakdown
The ONS have outlined the structure of their intended approach to modelling DB pension wealth in Round 8 in line with GADβs advice βvaluing defined benefit pension wealthβ paper dated 5 December 2024, summarised below:
ONS apply the above model to interviews with households in their sample in each wave/round.
The above formulation of the model covers the approach taken for deferred DB pension entitlements, where the ππ pension payable may be known. Where interviewees remain active participants in their DB pension scheme, we understand this accrued value is calculated as:
πππππ’ππ πππ‘π Γ π πππ£πππ Γ ππππ πππππππ π πππππ¦;
There may be some scheme specific constraints that limit the pensionable salary definition or the maximum eligible service that are ignored. For interviewees currently in receipt of their pension, the period of discounting applied on the bottom of the equation is nil. Therefore, the wealth is derived solely from the in-payment pension ππ and the relevant annuity factor.