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1 min readWarningBank of England taxonomy 2.2.0Updated 11 November 2026

Best estimate assumptions for life insurance risks: a conditional check (IR.12.04, Bank of England rule IR_bv1268)

A warning on the best estimate assumptions for life insurance risks template (IR.12.04), in the annual solo (ARS) return.

Check your file for this ruleWhat to do if it fails

The rule in plain words

If any of the items "Previous year Y-1 basis" (C0020) or "Subcategory description" (C0090) of IR.12.04.01.02 R1470 ("Subcategory 2") is reported, the item "Subcategory 2, Valuation year Y basis" (IR.12.04.01.02 R1470 C0010) must also be reported

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 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. 03It runs only when your filing indicators mark IR.12.04 as reported.
  4. 04This 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

Best estimate assumptions for life insurance risks [number] (IR.12.04.01.02)

Row

  • R1470Subcategory 2

Columns

  • C0010Valuation year Y basis
  • C0020Previous year Y-1 basis
  • C0090Subcategory description

Which returns it applies to

Line4 Check runs it on annual solo (ARS) return on Bank of England taxonomy 2.2.0. The Bank of England applies it to annual solo (ARS) returns, as a warning.

The Bank’s own words and formula

In the Bank of England’s list of validations, word for word:

If one of columns C0020 or C0090 is reported, then C0010 should also be reported.
Show the formulaShow

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

if not(isNull({t: IR.12.04.01.02, r: R1470, c: C0020})) or not(isNull({t: IR.12.04.01.02, r: R1470, c: C0090})) then (not(isNull({t: IR.12.04.01.02, r: R1470, c: C0010}))) else true()

Every Solvency UK rule on IR.12.04

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.