Which large banks lead in cloud adoption, and which are fully cloud-based?

Which banks disclose the most about moving to the cloud?

The 30 highest of 74 banks with a cloud number, dated cloud move or cloud use case on their page. Columns: the disclosed cloud figure (or the completion statement where there is no figure), the public-cloud providers named anywhere on the bank's page, the latest dated cloud or data-centre move, and the evidence behind the score. Status reads the record: "migration complete or all-in" where the bank says it has finished, exited its data centres or is all-in on one provider.

Each row quotes the bank's page on this site; the bank link opens the full record with every source. “Not disclosed” means the page records nothing on that point. Banks absent from the table have no evidence on this topic on their page.

Which public-cloud providers do the large banks name?

Every provider named in the qualifying banks' records and the banks that name it. Most large banks name two or three: a bank with AWS and Azure in the table is multi-cloud by disclosure, not necessarily by design.

How is this ranking computed?

Score = 3 × disclosed numbers whose label or value mentions cloud, data centres, serverless, containers, Kubernetes, microservices, mainframes or a migration to a named provider + dated timeline moves mentioning any of those or a provider (AWS, Azure, Google Cloud, Oracle Cloud, IBM Cloud; capped at 4) + use cases on the same subjects (capped at 2) + 1 per public-cloud provider named on the bank's page (capped at 3) + 12 where a cloud number, move or key point says the bank is all-in on a named cloud, has closed its last data centre or exited its data centres, has completed a cloud migration or has 100% of applications on cloud + 2 per entry mentioning serverless, Lambda, Kubernetes, containers or microservices (capped at 2 entries) + cloud mentions among the bank's key points and section rows (capped at 2). Ties by assets, then name. Only entries already on the bank's page count; each is sourced there.

"Fully cloud-based" is read from the bank's own wording (all-in on a named cloud, last data centre closed, data centres exited, migration completed, 100% of applications on cloud), never inferred from a percentage short of that; a bank at 90% of applications on cloud is "migrating".

What are the caveats?

This ranks disclosure of cloud migration, not the share of workloads on cloud. Capital One, which says it closed its last data centre in 2020 and has run on AWS since, has less to report each year than a bank mid-migration, so recency works against early movers. Banks that run large private clouds and say little about public cloud are understated.

Cloud percentages use different bases (applications, workloads, infrastructure, compute) and cannot be compared across banks; a named provider says nothing about how much runs there. Core-banking replacement on a cloud-native core (Thought Machine, Finxact, Mambu) counts as a cloud move because the banks describe it that way.

How does this differ from the AI index?

The AI index has no cloud component. The modern-technology-stack ranking counts cloud alongside core-banking and API modernisation; this page isolates cloud, adds the providers named, the completion statements and serverless evidence, and answers which banks say they are fully cloud-based. The AI index and its method are on their own page; the technology leaders and generative AI guides are hand-written cross-bank tables with their own sourcing.