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

‌Market risk: authorisations - Trading book and market risk thresholds (MKR AUTH): calculation of the asset as a % of total assets (OF90.00.01.01, Bank of England check boe_b0312)

A blocking check on the ‌Market risk: authorisations - Trading book and market risk thresholds (MKR AUTH) template (OF90.00.01.01), 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.

Check your file for this ruleWhat to do if it fails

The rule in plain words

Calculation of the asset as a % of total assets

In each of "Month 3" (row 0010), "Month 2" (row 0020) and "Month 1" (row 0030) of ‌Market risk: authorisations - Trading book and market risk thresholds (MKR AUTH) (OF90.00.01.01): if "Total assets" (column 0080) is not zero, "in % of total assets" (column 0070) must equal "On- and off-balance sheet business subject to market risk" (column 0010) divided by "Total assets" (column 0080).

What to do if your return fails it

  1. 01Open the table below and find the cells the rule reads.
  2. 02The check applies only when its first part holds in your return. When it does, the second part must hold too: fix the second part, or correct the first.
  3. 03The Bank of England allows a small rounding difference, worked out from the decimals each value is reported with.
  4. 04It runs only when your filing indicators mark OF90.00.01.01 as reported.
  5. 05This is a blocking check. A return that fails it is normally rejected, so fix it before you submit.

The cells it reads

‌Market risk: authorisations - Trading book and market risk thresholds (MKR AUTH) (OF90.00.01.01)

Rows

  • R0010Month 3
  • R0020Month 2
  • R0030Month 1

Columns

  • C0010On- and off-balance sheet business subject to market risk
  • C0070in % of total assets
  • C0080Total assets

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}.

if ({t: OF90.00.01.01, c: 0080} != 0) then {t: OF90.00.01.01, c: 0070} = {t: OF90.00.01.01, c: 0010} / {t: OF90.00.01.01, c: 0080} else true()

Where it applies, in the Bank's words (its scope):

scope({t: OF90.00.01.01, r:0010;0020;0030, f: banking, fv: banking_reporting})

Every PRA banking rule on OF90.00.01.01

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.