1 min readBlockingBank of England banking taxonomy 4.1.1Updated 11 November 2026

Market risk: ASA residual risk add on (AS9 RRAO): deriving total risk exposure from own funds requirements (OF91.09.01.01, OF02.00.01.01, Bank of England check boe_b0547)

A blocking check on the market risk: ASA residual risk add on (AS9 RRAO) (OF91.09.01.01) and own funds requirements (CA2) (OF02.00.01.01) templates, in the own funds (PRA001) return.

Line4 Check runs it on the own funds (PRA001) return, proven on test files, check by check: the same outcome on all three test files of that return.

The rule in plain words

Deriving total risk exposure from own funds requirements

In row "Total Residual Risk Add-on (RRAO)" (0010) of Market risk: ASA residual risk add on (AS9 RRAO) (OF91.09.01.01): "Total risk exposure amount" (column 0030) must equal "Own funds requirements" (column 0020) multiplied by 12.5.

This is a blocking check. A return that fails it is normally rejected, so fix it before you submit. It runs only when your filing indicators mark OF91.09.01 as reported.

The cells it reads

Own funds requirements (CA2) (OF02.00.01.01)

Row

  • R0574Residual risk add-on (RRAO)

Column

  • C0010All approaches

Market risk: ASA residual risk add on (AS9 RRAO) (OF91.09.01.01)

Row

  • R0010Total Residual Risk Add-on (RRAO)

Column

  • C0020Own funds requirements

Which returns it applies to

Line4 Check runs it on the own funds (PRA001) return on Bank of England banking taxonomy 4.1.1. The Bank of England applies it to own funds (PRA001) returns, as a blocking check.

The Bank’s own words and formula

The first paragraph of the plain words above is the Bank of England’s own, word for word, from its list of validations. The second spells out its formula, with each cell named from its templates.

Show the formulaShow

The Bank of England's formula. Cells are written as {t: table, r: row, c: column}.

{t: OF91.09.01.01, r: 0010, c: 0030} = {t: OF91.09.01.01, r: 0010, c: 0020} * 12.5

Every PRA banking rule on OF91.09.01.01

Checks like this one, run at the point of submission, are the first step to real-time supervision. Line4 builds SupTech software for financial regulators that runs checks like these as each return arrives.