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

General information (MRL001): the LEI must follow a valid pattern (20 alpha-numeric characters) (MR700.00.01.01, Bank of England check boe_b4001)

A blocking check on the general information (MRL001) template (MR700.00.01.01), in the MREL resources (MRL001) return.

Line4 Check runs it on the MREL resources (MRL001) return, proven on test files, check by check: the same outcome on all eight test files of that return.

The rule in plain words

The LEI must follow a valid pattern (20 alpha-numeric characters)

In General information (MRL001) (MR700.00.01.01): "LEI" in column "Values" (row 030, column 010) must be in the format 18 capital letter or digits, then 2 digits.

What to do if your return fails it

  1. 01Open the table below and find the cells the rule reads.
  2. 02Compare the code or text in your return with the format the rule sets out, character by character, including any prefix and any spaces.
  3. 03It runs only when your filing indicators mark MR700.00.01 as reported.
  4. 04This is a blocking check. A return that fails it is normally rejected, so fix it before you submit.

The cells it reads

General information (MRL001) (MR700.00.01.01)

Row

  • R030LEI

Column

  • C010Values

Which returns it applies to

Line4 Check runs it on the MREL resources (MRL001) return on Bank of England banking taxonomy 4.1.1. The Bank of England applies it to MREL resources (MRL001) 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}.

matches({t: MR700.00.01.01, r: 030, c: 010}, "^[A-Z0-9]{18}[0-9]{2}$")

Every PRA banking rule on MR700.00.01.01

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.