This note is provided for the UK Atomic Energy Authority (UKAEA or the Authority) in its role as manager of the Combined Pension Scheme and the Principal Non-Industrial Superannuation Pension Schemes ("the UKAEA Schemes").

The purpose of the note is to provide the Authority with guidance on the calculation of the pension payable to a member on the conversion of a cash payment, such as a lump sum on retirement, into scheme pension ('Inverse commutation'), and accompanying guidance to demonstrate how these factors should be applied.

This guidance applies to members when exchanging part of their lump sum at retirement for additional pension under the Schemes' rules.

The following changes have been made when reviewing this guidance:

• Important information around the expected audience for the guidance, use of the guidance, review of factors, compliance and limitations applies across all sets of guidance. Rather than being repeated in each set of guidance, this can now be found on the scheme home page. It is important to read this information alongside the guidance.
• Calculation methodology: No changes have been made to the calculation methodology.
• Examples: There are no examples in this guidance. Worked examples, using the calculation methodology, can be found in prior versions of the guidance (though please note that these use historic factors).
• Factor tables: The "Factor Tables" tab contains the names of the tables that are referenced in the calculation methodology. The tables of factors themselves can be found in the most recently published "Consolidated Factors Workbook" which is available by clicking the "Download current Consolidated Factors Workbook" button on the scheme's home page.
• Assumptions: The key assumptions underlying the factors in each note are contained in the Consolidated Factors Workbook.
• Regulations: The regulations that require the production of the actuarial factors and/or guidance that is the subject of this note are summarised in the "Regulations" tab.

Factors are not provided for members younger than 55 years. Any cases in which the member is younger than 55 years should be referred to the Government Actuary's Department (GAD).

This guidance does not cover pension credit members, please refer to the latest pension on divorce guidance for pension credit members.

We do not envisage any other special cases not covered by this note. However, if any do occur they should be referred to GAD.