Amazon Web Services, Microsoft Azure and Google Cloud Platform are the three dominant hyperscale cloud providers. All three operate data centres within the UK — AWS and GCP in London, Azure in London and Cardiff — which matters when your application handles personal data subject to UK GDPR and when your contracts or sector rules require data to remain on British soil.
Decision summary: Compare the exact services, regions, identity model, operating skills, resilience, support and exit path in the proposed architecture.
Despite overlapping marketing claims, the three platforms are not interchangeable substitutes. They differ in service breadth, pricing structures, integration with existing business software, and the skills required to operate them effectively. The right choice depends less on which provider is objectively "best" and more on how your web application, SaaS product or internal system actually works.
| Cloud decision | What it changes | What to verify |
|---|---|---|
| Where the three platforms diverge | AWS has the largest catalogue of services and the longest track record. | Verify service scope, region, customer responsibility and recovery evidence. |
| UK-specific factors that matter | Data residency is the most immediate concern. | Verify service scope, region, customer responsibility and recovery evidence. |
| Internal business systems and CRM replacements | If you are replacing spreadsheets, building a CRM, or creating an admin portal for operational staff, the cloud provider's identity integration often decides the question. | Verify service scope, region, customer responsibility and recovery evidence. |
| SaaS products with multi-tenant architecture | For a SaaS founder planning a multi-tenant application, the decision often comes down to database strategy and container orchestration. | Verify service scope, region, customer responsibility and recovery evidence. |
Compare the services you will actually use
A platform-level comparison becomes outdated quickly. Region availability, residency commitments, managed-service features, support plans, identity integration and pricing differ by product and can change. Build the decision around a documented architecture and verify every critical claim in the current provider documentation and contract.
All three platforms use a shared-responsibility model. The provider secures parts of the underlying cloud, while the customer remains responsible for areas such as data, identities, application design and configuration to a degree that varies with the service model.
Where the three platforms diverge
AWS has the largest catalogue of services and the longest track record. It tends to suit teams that want granular control over infrastructure and a wide selection of managed databases, messaging services and integration options. The partner ecosystem in the UK is large, which affects the pool of available contractors and agencies.
Azure integrates tightly with the Microsoft ecosystem: Active Directory for identity, Office 365 for productivity, Teams for communication and .NET for development. If your business already relies on Microsoft licences, Azure often reduces friction in single sign-on, identity management and compliance reporting.
GCP has a smaller overall service catalogue but strengths in data analytics, containerised workloads and machine learning tooling. Its pricing model for compute can be more straightforward, and its Kubernetes offering (GKE) is widely regarded as mature. GCP's UK partner ecosystem is smaller, which can affect sourcing specialist support.
UK-specific factors that matter
Data residency is the most immediate concern. Storing and processing personal data of UK residents within UK-based data centres satisfies many contractual and regulatory expectations, but the specifics depend on your sector — financial services, healthcare and public-sector contracts often impose additional requirements. Check the provider's current compliance certifications and confirm with your legal adviser whether a particular region and certification set meets your obligations.
Billing currency is another practical difference. AWS and GCP typically bill in US dollars unless you negotiate otherwise, which introduces exchange-rate exposure into your operating costs. Azure bills in pounds sterling for UK accounts, which simplifies budgeting for some finance teams. The impact depends on your contract size and how your business manages currency risk.
Internal business systems and CRM replacements
If you are replacing spreadsheets, building a CRM, or creating an admin portal for operational staff, the cloud provider's identity integration often decides the question. If your organisation uses Microsoft 365 and Microsoft Entra ID for staff logins, building on Azure typically allows you to reuse existing security policies, group memberships and conditional-access rules without duplicating identity infrastructure. AWS and GCP both support SAML and OIDC federation with Microsoft Entra ID, but the setup is an additional integration rather than a native connection.
SaaS products with multi-tenant architecture
For a SaaS founder planning a multi-tenant application, the decision often comes down to database strategy and container orchestration. AWS offers the widest range of managed database engines, which matters if your product needs a specific data model. GCP's strength in Kubernetes can simplify container-based tenant isolation. Azure sits in the middle, with solid managed database options and adequate Kubernetes support, plus the advantage of native integration if your SaaS targets Microsoft-centric business customers.
Subscription billing integration is another factor. If your SaaS relies on Stripe, Paddle or a similar billing service, the cloud provider is largely irrelevant to the payment flow — the integration runs over APIs regardless. The provider matters more for the compute, database and queuing services that support your application logic.
Legacy system modernisation
When modernising a legacy application, the existing technology stack narrows the field. A system built on .NET Framework with Windows dependencies moves to Azure more naturally. A system built on Linux, PostgreSQL and open-source tooling may fit AWS or GCP with less rework. The cost and risk of re-architecting for a specific cloud platform should be weighed against the benefits before committing.
Data-heavy workloads and reporting
If your web application generates large volumes of operational data that feed into reporting or analytics pipelines, GCP's BigQuery and data-tooling ecosystem offer a distinct advantage for query performance at scale. AWS provides Redshift and a broader set of data-warehouse options. Azure offers Synapse Analytics with deep Power BI integration, which matters if your business already uses Microsoft's reporting tools.
Choosing on brand rather than requirements
The most frequent error is selecting a provider based on familiarity or market share without mapping the decision to specific technical and commercial requirements. A useful discipline is to list the services your application actually needs — database type, identity integration, message queuing, file storage, monitoring — and compare what each provider offers for those specific components before committing.
Ignoring egress and data-transfer costs
All three providers charge low rates for data entering their networks but significantly more for data leaving. If your web application serves large files to users, streams data to external systems, or pushes high volumes to a third-party integration, egress charges can become a meaningful part of your hosting bill. Compare the egress pricing tiers for your expected traffic patterns rather than focusing solely on compute costs.
Overlooking team skills and hiring
The cloud provider you choose affects recruitment, supplier choice and operational continuity. Talent availability varies by region, sector and workload, so verify the capability of the actual delivery and support team rather than relying on broad claims about certification numbers. If your existing development team has deep Azure or GCP experience, the cost of retraining or hiring for a different platform should factor into the decision. Ask your development team which platform they can operate safely and support without a learning curve that delays delivery.
Assuming compliance is automatic
Using a UK data centre does not by itself guarantee compliance with UK GDPR, sector-specific regulations or customer contractual requirements. Each provider publishes an extensive set of compliance certifications, but you remain the data controller and carry responsibility for configuring the environment correctly — encryption settings, access controls, logging and data-retention policies. Review the provider's current compliance documentation, confirm it covers your specific regulatory context, and ensure your architecture and operational practices close any gaps.
Not planning for exit
Vendor lock-in is a structural risk with any hyperscale provider. Proprietary services — AWS Lambda, Azure Cosmos DB, Google Firestore — offer convenience but make future migration more expensive. If exit flexibility matters to your business, prefer open-source-compatible services (PostgreSQL over a proprietary database, standard Kubernetes over a serverless container service) and ensure you retain control of your data, domain names and application code. The detailed mechanics of exit planning are covered separately, but the principle should influence your architecture decisions from the start.
Key checks before committing
- Confirm which UK regions each provider offers and whether they meet your data-residency requirements.
- Compare the specific managed services you need — not the total catalogue, but the ones your architecture depends on.
- Review egress pricing against your expected data-transfer patterns.
- Assess your team's existing skills and the local availability of specialist support.
- Check the provider's current compliance certifications against your sector obligations.
- Understand the billing currency and whether exchange-rate fluctuations affect your budgeting.
- Identify which components in your architecture use proprietary services and what the migration cost would be if you needed to move.
The general process for evaluating and selecting a cloud provider is covered in the preceding guide. For a different angle on infrastructure — comparing cloud hosting with traditional dedicated servers — the next article in this section examines when each approach is appropriate.
Cloud claims to verify before procurement
- List the exact provider services and data flows that the decision covers.
- Recheck current service availability, residency commitments and commercial terms before procurement.
- Assess the exact services and regions in scope; a provider-level statement does not describe every product or data flow.
- Document customer responsibilities for identity, configuration, data protection, logging, backups and recovery.
Primary guidance checked for this edition
Sources for “AWS vs Azure vs Google Cloud for UK Businesses” were checked on 22 July 2026. Recheck the applicable rules, product documentation and contractual terms before implementation because these can change after the review date.