Independent model validation: IFRS 9 for treasury and mortgages
A European bank commissioned an independent second-line validation of the IFRS 9 ECL models covering its mortgage and treasury books.
The bank bought its models, so documentation was their only account, and code cannot be assumed to match it.
What We Provided
Numbers that start from data the committee can trust
The loan-level datasets were reproduced independently and agreed to the external provider's own audit summaries, then the distribution of every variable feeding the probability of default model was monitored for drift.
Questions answered on the record
A logged query process with the first line meant every question raised carried a documented answer. Those answers became evidence in their own right and surfaced what documentation alone never exposes.
A read on how much headroom the model has
Challenger models reproduced on the same data, benchmarked against the incumbent and measured on unseen data, put a size on the loss of accuracy and discrimination and separated data drift from specification.
The whole ECL chain, not only the models
The expected credit loss calculation framework, the staging logic and the governance and documentation behind the models were all in scope, which is what lets one report speak to the whole number.
The Results
The committee received a full validation report and the memo carrying it. High-materiality actions landed on the macroeconomic and mortgage PD models, and management committed them to a remediation plan with a named owner and a date.
Other Case Studies
Independent validation of a Pillar 2A concentration add-on
A European bank needed to know that the capital it holds against concentrated lending would stand up to scrutiny, so it asked us for an independent view of the model behind the number.
Redeveloping every IFRS 9 model across two portfolios
A UK lender needed every model in its IFRS 9 expected credit loss suite rebuilt, at the point when the team that had built them was no longer there.