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A UK CIO we spoke to in June signed off a cloud migration on a lift-and-shift quote of £180k. By month four his team had discovered three workloads that could not run on standard EC2 without significant refactor. His revised bill was £340k. His CFO was not happy.
That gap between the quote and the outturn is where most SME cloud migrations lose credibility. This article is a candid 2026 playbook. The Six R's with real per-workload cost. The hidden costs that consultants under-quote. An honest AWS versus Azure versus GCP read for SMEs. And the failure modes we see repeatedly across UK and US migrations.
If you are the CTO, IT Director, or Finance Director scoping the programme, this is written for you.
The Six R's of Cloud Migration and Real 2026 Costs
Six approaches per workload with real 2026 numbers.
Retire (£2k to £10k per workload). Turn the app off, archive data, redirect users. Fastest ROI. Typically 15 to 25 percent of an SME's workload inventory is genuine retire candidate.
Retain (£0 migration). Keep on-premise for compliance, latency, or licence reasons. Real cost is rising infrastructure spend on ageing hardware.
Rehost or lift-and-shift (£5k to £30k per workload, 2 to 6 weeks). Move VM to cloud VM (EC2, Azure VM, GCE) without code change. Best for stable apps with 3 to 5 years of remaining useful life. Simplest, fastest, cheapest.
Replatform (£15k to £70k per workload, 6 to 16 weeks). Minor changes to use managed services: move database to RDS, replace scheduler with EventBridge, replace load balancer. Best for apps with 5 to 10 years of remaining life where managed services materially reduce ops burden.
Refactor (£60k to £300k+ per workload, 4 to 12 months). Deep restructure to cloud-native architecture (microservices, containers, serverless). Best for strategically important apps where the cloud-native version delivers business value beyond cost savings.
Repurchase (£20k to £100k migration and setup). Replace bespoke app with SaaS (Salesforce, Workday, NetSuite). Best when the app does something standard and your customisation was mostly cosmetic.
For a 50-person UK or US SME with 15 to 25 workloads, typical mix: 15 to 25 percent retire, 30 to 40 percent rehost, 20 to 30 percent replatform, 10 to 15 percent refactor, 5 to 10 percent repurchase. Total programme cost lands £120k to £450k across 6 to 12 months. Our earlier post on enterprise software modernisation covers the larger-enterprise version of this framework.
Hidden Costs That Turn £200k Quotes into £400k Bills
Five costs commonly under-quoted or missed.
Egress fees. Data out of the cloud. AWS $0.09 per GB (first 10TB) declining tiers. Azure $0.087 per GB tier 1. GCP $0.11 per GB standard. For a workload pushing 5TB per month egress, monthly egress bill lands £350 to £500. At 20TB per month, £1.4k to £2.0k monthly. Consultants often quote based on ingress data only.
Licence overlap during transition. Running old and new in parallel for 3 to 9 months. £20k to £150k depending on estate size. Rarely fully modelled in the initial quote.
Cross-region and cross-zone data transfer. Moving data between regions for disaster recovery or between availability zones for high availability. $0.01 to $0.02 per GB. At high volume, this compounds.
Reserved instance or savings plan mismatch. Committing to 3-year reserved instances based on projected usage, then discovering actual usage is 60 percent of forecast. Wasted commitment. Model conservative usage.
Post-migration optimisation. The programme is not done when apps land in cloud. Rightsizing, unused resource cleanup, tuning takes 3 to 6 months and 15 to 25 percent of migration budget. Rarely in the initial quote.
Total hidden costs commonly add 40 to 80 percent to the headline programme number. Include them from day one or discover them in month five.
AWS vs Azure vs GCP for SMEs in 2026
Real 2026 pricing for a representative workload (mid-size web app, 4 vCPU, 16GB RAM, managed database, moderate egress).
AWS.
Compute (t3.large): ~$60/month
Managed DB (RDS PostgreSQL small): ~$100/month
Egress: $0.09/GB (first 10TB), scaling down
Best for: broadest catalogue, mature services, scale-out patterns
Learning curve: steepest of the three
Azure.
Compute (D4s v5): ~$140/month
Managed DB (Azure Database for PostgreSQL): ~$180/month
Egress: $0.087/GB tier 1
Best for: Microsoft-stack SMEs (Active Directory, Office 365, Windows Server, SQL Server), hybrid architectures
Enterprise integration: strongest
GCP.
Compute (e2-standard-4): ~$100/month
Managed DB (Cloud SQL PostgreSQL): ~$130/month
Egress: $0.11/GB standard, more competitive with commitments
Best for: AI/ML workloads (BigQuery, Vertex AI), data analytics
UK partner network: smallest of the three
For most UK and US SMEs already on Microsoft (Office 365, Windows Server, SQL Server), Azure wins on integration and existing team skills. For SMEs building modern applications from scratch or scaling data-heavy workloads, AWS or GCP often edges ahead. See AWS Migration Acceleration Program and Azure Migration and Modernization Program for the migration credit and partner support the hyperscalers offer.
When Lift-and-Shift Actually Wins
Three scenarios where rehost beats deeper refactor.
Data centre exit under time pressure. Contract ending, lease expiring, hardware end-of-life. Time-to-cloud matters more than long-term optimisation.
Workloads with 3 to 5 years of remaining useful life. No point refactoring an app you plan to retire in 3 years. Rehost, run, retire.
Refactor budget does not exist. SMEs with limited engineering capacity often cannot afford deep refactor. Rehost first, replatform later, refactor only what earns it.
The mistake is lift-and-shifting apps that should have been retired, replaced with SaaS, or replatformed. That leaves cloud bills that stay high year after year without operational improvement.
What We Learned Migrating a UK Property Platform to Cloud
We migrated a UK property developer platform we built for from on-premise VMs to AWS in 2024. Estate: 12 workloads, 3 databases, ~200 concurrent users, moderate but bursty traffic. Two lessons.
Egress from data-heavy workloads dominates the surprise. Their PDF report generation service pushed 4TB monthly to end users. On-premise this was free. On AWS the egress bill landed £320 monthly. We rebuilt the report distribution to use CloudFront for cached delivery. Egress dropped 70 percent. Bill dropped 60 percent. Lesson: model egress before committing.
Rightsizing needs 60 days of production data, not consultant estimates. Initial consultant recommendation had 40 percent more compute than needed. After 60 days of production monitoring we rightsized down. Compute bill dropped 32 percent. Do not commit to reserved instances or savings plans until you have real production data.
You can see our work at our portfolio. If you want a candid migration audit for your specific estate, book a cloud migration audit with WhiteStone.
Common Failure Modes
Three failure modes we see repeatedly.
Signing off on lift-and-shift pricing without workload audit. Consultant quotes £150k, workload assessment reveals 4 apps need refactor before cloud will host them. Cost doubles.
Underestimating egress at design time. Data-heavy workloads (video, PDF, large downloads) can consume 30 to 50 percent of the cloud bill just in egress. Model this early.
Committing to reserved instances before rightsizing. Buy 3-year commitment based on on-premise usage. Reality: cloud usage is 60 percent of that. Wasted spend.
Frequently Asked Questions
What is a realistic cloud migration budget for a 50-person SME?
For 15 to 25 workloads across a typical 6 to 12 month programme, total cost lands £120k to £450k depending on Six R's mix. Add 40 to 80 percent for hidden costs (egress, licence overlap, cross-region transfer, post-migration optimisation). Total realistic outturn: £170k to £810k.
Is lift-and-shift cheaper than refactoring?
Cheaper upfront, sometimes more expensive over 3 years. Lift-and-shift lands £5k to £30k per workload. Refactor lands £60k to £300k+ per workload. But refactored apps typically run 30 to 60 percent cheaper on cloud due to managed services and rightsizing. Break-even at 18 to 30 months for the average workload.
How do egress fees actually work?
Data leaving the cloud (to end users, to other clouds, cross-region). AWS $0.09 per GB (first 10TB), Azure $0.087 per GB tier 1, GCP $0.11 per GB standard. A workload with 5TB monthly egress costs £350 to £500 monthly. High-egress workloads (video streaming, PDF distribution) can hit £2k to £20k monthly.
AWS or Azure for a UK SME?
Azure wins for Microsoft-stack SMEs already on Office 365, Active Directory, and Windows Server. AWS wins for broader catalogue, mature services, and scale-out patterns. Neither is dramatically cheaper on compute. Egress and managed service pricing are close. Existing team skills matter more than list prices.
How long does a typical SME migration take?
For 15 to 25 workloads across 6 to 12 months. Discovery and planning 6 to 10 weeks. Retire and rehost first wave 8 to 16 weeks. Replatform and refactor second wave 12 to 20 weeks. Post-migration optimisation 12 to 24 weeks. Rushed migrations under 6 months usually skip retire and optimisation and cost more over 3 years.
The One Thing to Remember
Cloud migration cost is not the quote. It is the quote plus egress plus licence overlap plus rightsizing plus optimisation. Programmes that stay on budget model these upfront. Programmes that go 40 to 80 percent over budget discover them in month five. If you want a defensible programme number for the board, add 40 to 60 percent to whichever consultancy quote looks lowest.
If you want a candid audit of your specific estate against real 2026 costs, browse our cloud solutions services or come to the audit call.
