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

Own funds (CA1): a total must equal the sum of its parts (C01.00.01.01, SC01.00.01.01, Bank of England check v0184_m)

A blocking check on the own funds (CA1) (C01.00.01.01) and own funds for SDDTs (CA1 SDDT) (SC01.00.01.01) templates, in the own funds (PRA001) and own funds for SDDTs (PRA116) returns.

Line4 Check runs it on the own funds (PRA001) and own funds for SDDTs (PRA116) returns, proven on test files, check by check: the same outcome on all six test files of those returns.

The rule in plain words

In column "Amount" (0010) of Own funds (CA1) (C01.00.01.01): "(-) Own AT1 instruments" (row 0580) must equal the sum of "(-) Direct holdings of AT1 instruments" (row 0590), "(-) Indirect holdings of AT1 instruments" (row 0620) and "(-) Synthetic holdings of AT1 instruments" (row 0621).

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. 02Add up the parts in your return and compare the result with the total.
  3. 03If they differ, a part is missing, a value sits in the wrong cell, or the total is out of date.
  4. 04The Bank of England allows a small rounding difference, worked out from the decimals each value is reported with.
  5. 05It runs only when your filing indicators mark C01.00.01 as reported.
  6. 06This is a blocking check. A return that fails it is normally rejected, so fix it before you submit.

The cells it reads

Own funds (CA1) (C01.00.01.01)

Rows

  • R0580(-) Own AT1 instruments
  • R0590(-) Direct holdings of AT1 instruments
  • R0620(-) Indirect holdings of AT1 instruments
  • R0621(-) Synthetic holdings of AT1 instruments

Column

  • C0010Amount

Own funds for SDDTs (CA1 SDDT) (SC01.00.01.01)

Rows

  • R0580(-) Own AT1 instruments
  • R0590(-) Direct holdings of AT1 instruments
  • R0620(-) Indirect holdings of AT1 instruments
  • R0621(-) Synthetic holdings of AT1 instruments

Column

  • C0010Amount

A worked example

With simple numbers.

Illustrative values
(-) Direct holdings of AT1 instruments1,200
(-) Indirect holdings of AT1 instruments800
(-) Synthetic holdings of AT1 instruments450
Together2,450
What the rule then expects

(-) Own AT1 instruments must then be 2,450.

2,450Passes
2,550Fails

A file that reports 2,450 passes. One that reports 2,550 fails, by 100.

The numbers are illustrative, reported to the unit, so the rounding tolerance does not change the result.

Which returns it applies to

Line4 Check runs it on the own funds (PRA001) and own funds for SDDTs (PRA116) returns on Bank of England banking taxonomy 4.1.1. The Bank of England applies it to own funds for SDDTs (PRA116) and own funds (PRA001) returns, as a blocking check.

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:

v0184_m: [C01.00.01.01] {r0580, c0010} = {r0590, c0010} + {r0620, c0010} + {r0621, c0010}
Show the formulaShow

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

{t: C01.00.01.01, r: 0580, c: 0010} = {t: C01.00.01.01, r: 0590, c: 0010} + {t: C01.00.01.01, r: 0620, c: 0010} + {t: C01.00.01.01, r: 0621, c: 0010}

Every PRA banking rule on C01.00.01.01

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.