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2 min readWarningBank of England banking taxonomy 4.1.1Updated 11 November 2026

Capital adequacy - memorandum items (CA4): a conditional check (C04.00.01.01, C01.00.01.01, Bank of England check v4811_m)

A warning on the capital adequacy - memorandum items (CA4) (C04.00.01.01) and own funds (CA1) (C01.00.01.01) 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.

Check your file for this ruleWhat to do if it fails

The rule in plain words

In Capital adequacy - memorandum items (CA4) (C04.00.01.01): if "IRB excess (+) or shortfall (-) of credit risk adjustments, additional value adjustments and other own funds reductions to expected losses for non defaulted exposures" in column "Amount" (row 0100, column 0010) is less than 0 and "IRB excess (+) or shortfall (-) of specific credit risk adjustments to expected losses for defaulted exposures" in column "Amount" (row 0145, column 0010) is less than 0, "(-) IRB shortfall of credit risk adjustments to expected losses" in column "Amount" (row 0380, column 0010) in Own funds (CA1) (C01.00.01.01) must equal the sum of "IRB excess (+) or shortfall (-) of credit risk adjustments, additional value adjustments and other own funds reductions to expected losses for non defaulted exposures" in column "Amount" (row 0100, column 0010) and "IRB excess (+) or shortfall (-) of specific credit risk adjustments to expected losses for defaulted exposures" in column "Amount" (row 0145, column 0010).

The headline gives only the template and the kind of check, because the rule is too long to say in a headline. The plain words above say all of it.

What to do if your return fails it

  1. 01Open the tables 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 C01.00.01 and C04.00.01 as reported.
  5. 05This is a warning. It does not stop the return on its own, but your supervisor may ask you to explain it.

The cells it reads

Own funds (CA1) (C01.00.01.01)

Row

  • R0380(-) IRB shortfall of credit risk adjustments to expected losses

Column

  • C0010Amount

Capital adequacy - memorandum items (CA4) (C04.00.01.01)

Rows

  • R0100IRB excess (+) or shortfall (-) of credit risk adjustments, additional value adjustments and other own funds reductions to expected losses for non defaulted exposures
  • R0145IRB excess (+) or shortfall (-) of specific credit risk adjustments to expected losses for defaulted exposures

Column

  • C0010Amount

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 warning.

The Bank’s own words and formula

The plain words above spell out the Bank’s formula, with each cell named from its templates. In the Bank of England’s list of validations, word for word:

[v4811_m];[if {t: C04.00.01.01, r: 0100, c: 0010} < 0 and {t: C04.00.01.01, r: 0145, c: 0010} < 0 then {t: C01.00.01.01, r: 0380, c: 0010} = {t: C04.00.01.01, r: 0100, c: 0010} + {t: C04.00.01.01, r: 0145, c: 0010} else true()]
Show the formulaShow

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

if {t: C04.00.01.01, r: 0100, c: 0010} < 0 and {t: C04.00.01.01, r: 0145, c: 0010} < 0 then {t: C01.00.01.01, r: 0380, c: 0010} = {t: C04.00.01.01, r: 0100, c: 0010} + {t: C04.00.01.01, r: 0145, c: 0010} else true()

Every PRA banking rule on C04.00.01.01

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.