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Hidden costs of cloud migration and how SMBs can avoid them

AUG 25 2024   -   8 MIN READ
Sep 17, 2025
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6 MIN READ
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Modernize your cloud. Maximize business impact.

Cloud migration offers SMBs a clear path to modernizing outdated infrastructure, improving performance, and scaling with demand. But while the benefits are well understood, the true costs are often underestimated. From unplanned downtime to underused services and post-migration inefficiencies, these hidden costs can erode ROI if not addressed early.

This guide breaks down the key cost drivers SMBs should anticipate during a cloud migration, and how AWS-native tools can help monitor and control spending.

Key takeaways:

  • Without upfront planning, SMBs may face unexpected charges from overprovisioned resources, idle services, or unoptimized storage tiers.
  • Using tools like AWS Compute Optimizer and TCO Calculator helps align compute and storage to real-world workloads before migration begins.
  • Unplanned egress fees, legacy license constraints, and poorly planned cutovers can significantly raise migration expenses.
  • Clear tagging, budget alerts, and cost tracking with AWS Budgets and Cost Explorer help prevent cost sprawl and maintain visibility across teams.
  • Cloudtech combines technical precision with SMB-focused strategy to help businesses migrate smarter, avoiding common pitfalls and unlocking long-term cloud value.

What’s driving up cloud migration costs? 10 hidden risks and how to fix them

What’s driving up cloud migration costs? 10 hidden risks and how to fix them

More than just a lift-and-shift operation, cloud migration is a transformation of how data, compute, and applications are managed. For SMBs, overlooking cost drivers like overprovisioned instances, idle storage, or underused managed services can quickly undermine the value of the migration. These accumulate over months in the form of inflated AWS bills, unpredictable budget spikes, and underperforming workloads.

For example, an SMB that migrates its database workloads to Amazon RDS without optimizing instance size or enabling storage auto-scaling may end up paying for capacity it never uses, while also experiencing performance issues under peak load. 

SMBs can avoid surprises, preserve ROI, and ensure their cloud environments remain cost-effective and performant by identifying and mitigating such hidden costs early:

1. Overprovisioned compute resources

One of the most overlooked expenses during cloud migration is the cost of oversized compute instances. Many SMBs, aiming to avoid performance issues, default to Amazon EC2 instance types that far exceed their actual needs. They provision m5.2xlarge or c6i.large when a t3.medium or even a AWS Lambda-based architecture might suffice. These decisions are often made without baseline metrics, leading to unused CPU, underutilized memory, and inflated hourly billing.

How to fix it: SMBs should take a measurement-based approach before and after migration:

  • Use AWS Application Discovery Service to collect actual utilization data from on-prem workloads over time.
  • Use AWS Compute Optimizer to analyze usage patterns and recommend cost-efficient EC2 instance types based on actual CPU, memory, and I/O metrics.
  • Configure Auto Scaling Groups with performance-based policies, and replace always-on instances with AWS Lambda or Fargate for intermittent workloads.
  • Use the AWS Pricing Calculator and TCO Calculator to compare instance types, Savings Plans, and Reserved Instances.

Pro tip: AWS partners like Cloudtech support SMBs by conducting a detailed workload assessment and sizing exercise before migration. They also configure environment-wide tagging and automation scripts to detect and decommission underused resources post-migration, so excess spend doesn’t go unnoticed over time.

2. Data transfer and egress fees

While data storage in AWS (like S3 or RDS) is relatively predictable, data movement costs are often overlooked, especially when large volumes are transferred between services, across regions, or out of AWS entirely.

Two key cost drivers for SMBs:

  • Inter-AZ and inter-region transfers: Moving data between Availability Zones (AZs) or AWS Regions (e.g., from us-east-1 to us-west-2) incurs per-GB charges, even within the same account.
  • Data egress to the internet: Transferring data out of AWS (e.g., downloading from an Amazon S3 bucket or exposing APIs to external clients) is billed by GB, with no free tier after the first 100 GB/month.

For example, if a healthcare SMB regularly moves EHR backup files between regions for compliance without using regional services effectively, it may be incurring thousands per year in silent inter-region transfer fees.

How to fix it: SMBs can mitigate these costs with careful architecture and AWS-native controls:

  • Wherever possible, keep compute and storage services in the same region and AZ. Use Availability Zone Affinity for EC2 placement to reduce intra-AZ traffic.
  • For Amazon S3, DynamoDB, and other services, route traffic through VPC endpoints to avoid NAT gateway or internet transit charges.
  • Distribute content using Amazon CloudFront, reducing origin fetches and external bandwidth usage.
  • Set up AWS Cost Explorer with usage type filtering (DataTransfer-Out-Bytes) and create AWS Budgets alerts to catch spikes early.

Pro tip: For SMBs with regular cross-region replication or large outbound traffic (e.g., B2B data sharing, backups, public file downloads), Cloudtech can restructure the architecture using services like Amazon S3 Replication with intelligent lifecycle policies, AWS Global Accelerator, and private interconnects.

3. Storage sprawl

As SMBs migrate data to the cloud, storage usage often grows unchecked across services like Amazon S3, EBS, EFS, and RDS snapshots. Files are duplicated for testing, backups are retained longer than necessary, and old volumes are left orphaned. 

This uncontrolled growth, known as storage sprawl, leads to ballooning monthly bills, especially when data sits in higher-cost storage tiers like S3 Standard or unused provisioned EBS volumes.

Common scenarios include:

  • Development teams taking frequent snapshots of RDS or EBS volumes and forgetting to delete them.
  • Large media or log files accumulating in S3 buckets without lifecycle policies.
  • Test environments being spun up with duplicated datasets, then left running indefinitely.

Even storing 10 TB of unnecessary Amazon S3 data in Standard storage instead of S3 Glacier or S3 Intelligent-Tiering can add thousands in annual spend, with no business value returned.

How to fix it: Avoiding storage sprawl requires visibility, automation, and lifecycle enforcement:

  • Automatically transition infrequently accessed data to more cost-effective storage classes (e.g., S3 Intelligent-Tiering, S3 Glacier, or S3 Glacier Deep Archive) and delete expired objects.
  • Use Amazon Data Lifecycle Manager to automate snapshot creation and retention policies for volumes and AMIs.
  • Use AWS Trusted Advisor or Compute Optimizer to identify unattached EBS volumes and idle EFS instances.
  • Enable AWS Cost Explorer, filtered by usage type (TimedStorage-Snapshot, TimedStorage-ByteHrs) to catch spikes in unused or high-cost storage classes.
struggling with slow data pipeline

4. Idle resources post-migration

After migrating to the cloud, it’s common for SMBs to leave unused or underutilized resources running, especially temporary workloads spun up for testing or transitional services that are no longer needed. These “zombie resources” continue to generate monthly costs without delivering business value.

Examples include:

  • EC2 instances left running with no traffic or CPU usage.
  • EBS volumes detached from instances but still accruing storage charges.
  • RDS instances provisioned for staging environments and forgotten after go-live.
  • Load balancers, NAT gateways, or Elastic IPs idle but still metered by the hour.

Even a few idle t3.medium EC2 instances, unmonitored NAT gateways, or unused RDS databases can lead to hundreds or thousands of dollars per month in waste, especially for SMBs operating under tight budgets or cost constraints.

How to fix it: Post-migration optimization is essential to avoid long-term inefficiencies:

  • Create alarms for low CPU/network utilization on Amazon EC2, Amazon RDS, or AWS Lambda functions.
  • Implement resource tagging (e.g., env:dev, owner:team) and use AWS Resource Groups or AWS Config Rules to detect unused assets.
  • Continuously scan for underutilized or idle resources across EC2, EBS, ELB, and RDS.
  • Use Instance Scheduler on AWS to stop dev/test workloads outside business hours.
  • Use AWS Cost Explorer and Detailed Billing Reports (DBR) to identify persistent charges from low-activity resources.

Pro tip: For SMB clients, Cloudtech deploys automated tagging frameworks and idle resource cleanup scripts using AWS Lambda and EventBridge, along with weekly CloudWatch utilization reports.

5. License-related costs during rehosting

When SMBs migrate existing applications to AWS without rearchitecting (a lift-and-shift or rehosting strategy), they often carry over existing commercial licenses for databases, operating systems, or middleware without considering how cloud billing models differ from on-prem.

Two common issues emerge:

  • SMBs using Microsoft SQL Server, Windows Server, or Oracle under on-prem licensing may discover that these licenses don’t fully transfer to AWS EC2 or RDS environments, or require strict license mobility conditions.
  • If SMBs spin up EC2 instances with pre-installed licensed AMIs (e.g., Windows + SQL), but also pay for existing licenses separately, they end up paying twice, once to AWS and once to their legacy provider.

For example, rehosting a SQL Server workload to Amazon EC2 without checking the license mobility rights may force SMBs into paying AWS license-included pricing and their existing vendor’s fees, resulting in significant unexpected monthly costs.

How to fix it:

  • Use AWS License Manager and AWS Systems Manager Inventory to track all software licenses, editions, and terms prior to rehosting.
  • For workloads where BYOL isn’t viable, opt for AWS license-included EC2 AMIs to avoid vendor audits and compliance issues.
  • Before rehosting Microsoft or Oracle products, confirm terms with vendors. AWS offers Dedicated Hosts or License Manager options to support compliant BYOL.
  • Configure AWS Config rules or License Manager policies to prevent unauthorized deployments of licensed software.

Pro tip: For SMBs running commercial databases or licensed software, Cloudtech maps each workload to the most cost-effective AWS hosting model, whether that’s Amazon RDS with license-included pricing, Amazon EC2 with BYOL, or containerization to eliminate licenses entirely. 

6. Downtime during cutover

One of the most underestimated costs of cloud migration is business disruption during the final cutover, the moment when traffic and operations switch from legacy systems to the cloud. Even a few hours of downtime can impact SMBs significantly, leading to:

  • Lost revenue from unavailable customer-facing services (e.g., appointment booking platforms, payment systems).
  • Operational delays due to inaccessible internal systems like ERPs or CRMs.
  • Data inconsistency if records are modified during an uncoordinated switchover window.

For example, a healthcare SMB migrating its EHR system without a robust cutover plan could risk incomplete patient data syncing, impacting care continuity or compliance with HIPAA access controls.

How to fix it: Avoiding downtime during cutover requires incremental, tested transition strategies using AWS-native tools:

  • Replicate source servers in near real-time and run cutover rehearsals to validate performance, authentication, and connectivity before flipping the switch.
  • Create duplicate environments with Route 53 traffic shifting or Elastic Load Balancer listeners to allow seamless switchover without DNS propagation delays.
  • Use AWS Systems Manager Automation to orchestrate cutover workflows, ensuring tasks like final syncs, DNS updates, and user notifications are executed in the right order.
  • Run both legacy and cloud systems temporarily with sync tools like AWS DMS (for databases) or AWS DataSync (for file systems) to confirm functional parity before full transition.

7. Underutilized managed services

AWS offers a wide array of managed services like Amazon RDS, Amazon OpenSearch Service, AWS Glue, and Amazon MQ, which promise scalability and reduced operational overhead. However, many SMBs adopt these services without fully using their capabilities, resulting in recurring charges for features or capacity that aren’t aligned with actual usage.

Common examples include:

  • Running multi-AZ RDS instances for dev/test databases that don’t require high availability.
  • Launching Amazon EMR or Glue jobs on a schedule, even when no data needs processing.
  • Using Amazon OpenSearch with high IOPS EBS volumes and multiple nodes for low-volume logs.
  • Leaving Elastic Load Balancers (ELBs) active in environments with minimal traffic.

Because these services are billed by provisioned resources (not always by usage), idle or oversized configurations can add thousands annually in waste, especially for SMBs who assume “managed” means “optimized.”

How to fix it: Avoiding this trap requires performance tuning and usage-based configuration, using the following AWS tools and techniques:

  • For services like Amazon RDS and AWS DynamoDB, enable Auto Scaling or switch to Amazon Aurora Serverless v2, which adjusts capacity on-demand.
  • Use AWS CloudWatch to track query volume, CPU utilization, and memory pressure. Based on thresholds, pause or resize underused services (e.g., using RDS stop/start features).
  • Use AWS Compute Optimizer for RDS and Cost Explorer’s utilization reports to identify overprovisioned tiers.
  • Instead of running separate managed services per team or app, consolidate into shared resources with access controls (e.g., a central Glue job triggered by EventBridge for multiple apps).
  • Use AWS Resource Groups, tagging (env, team, owner), and Config Rules to auto-detect managed services with persistent underutilization.

Pro tip: Cloudtech performs periodic reviews of managed workloads, helping SMBs switch to serverless variants (like Aurora Serverless or Amazon Athena), and deploy usage-based triggers that automatically pause or scale services. 

8. Training and ramp-up time for teams

After migration, SMBs often find that internal teams aren’t fully prepared to operate or manage the new cloud environment. Unlike on-prem infrastructure, AWS introduces new concepts like auto-scaling groups, IAM roles, serverless workflows, usage-based billing, and managed services.

Without prior enablement:

  • Developers may misconfigure services like Amazon S3 or AWS Lambda, leading to performance bottlenecks or security gaps.
  • Ops teams may struggle with log aggregation, monitoring setups (e.g., CloudWatch, CloudTrail), or automated deployments.
  • Finance teams may misinterpret usage-based billing reports, resulting in confusion over cost spikes or chargebacks.

This lack of cloud fluency not only slows down adoption but also introduces risks of misconfiguration, non-compliance, and inefficient use of resources.

How to fix it: Cloud training should be role-specific, continuous, and closely tied to the workloads being migrated:

  • Enroll teams in curated learning paths such as “Cloud Essentials for SMBs,” “Operations in AWS,” or “Serverless App Development.” Many of these are free and designed for non-enterprise audiences.
  • Set up isolated AWS accounts or Control Tower organizational units (OUs) with budget alerts so teams can experiment safely without financial or production risk.
  • Create scoped IAM roles (e.g., read-only access, billing viewer, or dev sandbox admin) to let teams explore while maintaining security boundaries.
  • Align enablement with current or upcoming cloud features in the roadmap—e.g., train on Step Functions before rolling out a serverless pipeline.
  • Help finance and operations teams become fluent in tracking performance and spend from day one.

Pro tip: Cloudtech embeds enablement into every phase of the migration process, not as an afterthought. They deliver tailored onboarding plans that include access to AWS Skill Builder, deploy real-use sandbox environments with scoped permissions, and conduct team-specific sessions on tools like AWS CloudFormation, Amazon CloudWatch, and AWS Cost Explorer. 

9. Security misconfigurations post-migration

Post-migration, many SMBs assume that once data and workloads are live in AWS, security is automatically handled. But cloud security operates under a shared responsibility model, and SMBs should not overlook their side of the equation.

Common security misconfigurations include:

  • Public Amazon S3 buckets unintentionally exposing sensitive files.
  • Overly permissive IAM roles granting broad access across resources.
  • Disabled logging on critical services like Amazon RDS, Amazon EC2, or VPC flow logs.
  • Unencrypted data at rest or in transit, violating compliance standards like HIPAA or SOC 2.
  • Open ports or misconfigured security groups exposing workloads to the public internet.

These missteps can lead to data breaches, failed audits, and reputational damage, especially for SMBs handling regulated data like personal health information (PHI) or payment records.

How to fix it: AWS provides built-in tools and frameworks to enforce security policies proactively:

  • Tools like AWS Config and AWS Security Hub continuously evaluate resources against best practices and compliance baselines (e.g., CIS AWS Foundations Benchmark, HIPAA, PCI).
  • Ensure activity tracking is active across all regions with AWS CloudTrail and AWS CloudWatch Logs. Use log filtering to detect anomalies in authentication or API access.
  • Identify resources (like roles or S3 buckets) shared externally or misconfigured with broad access using IAM Access Analyzer.
  • Use AWS KMS for key management and enforce encryption on Amazon S3, EBS, and RDS by default.
  • Use VPC security group rules, Network ACLs, and AWS Firewall Manager to control and audit network access.

Pro tip: Cloudtech enforces AWS security best practices during and after migration. It pre-configures guardrails such as encryption policies, IAM role boundaries, and AWS Config compliance packs tailored to SMB environments. 

10. Unclear post-migration ownership and billing accountability

After cloud migration, SMBs often face internal confusion over who owns what — both technically and financially. Unlike traditional on-prem systems where infrastructure is centrally managed, cloud workloads can span multiple AWS accounts, projects, or business units. Without defined ownership:

  • Teams may unknowingly spin up redundant resources, leading to unexpected charges.
  • Cost anomalies go unnoticed because no one is actively monitoring usage.
  • Support incidents or access requests are delayed due to unclear administrative responsibility.
  • Finance teams struggle to reconcile cloud invoices with internal budgets or departments.

This lack of clarity leads to wasted spend, security risks, and friction between technical and business units.

How to fix it: Fixing this requires a governance model built around clear tagging, budgeting, and ownership practices:

  • Create a multi-account structure where each workload or department has a separate account with scoped access and budget enforcement.
  • Assign spend limits to teams or workloads using AWS Budgets and Budget Alerts. Send alerts if actuals or forecasts exceed thresholds.
  • Use mandatory cost allocation tags (owner, env, cost-center) and enforce them with AWS Tag Policies so every resource is traceable.
  • Enable granular cost analysis by project, environment, or team with AWS Cost Explorer. Use Resource Groups to group costs logically.
  • Assign ownership of each workload (both technical and financial) and conduct monthly reviews using AWS reports (e.g., CUR - Cost and Usage Reports).

Pro tip: Partnering with an experienced AWS provider early in the migration process helps SMBs avoid missteps that lead to long-term cost creep. From right-sizing compute to enforcing security and billing policies, certified partners like Cloudtech ensure every phase is optimized.

How does Cloudtech help SMBs control migration costs from day one?

Cloudtech helps SMBs reduce the risk of budget overruns by aligning cloud migration strategy with cost control from the very beginning. Instead of reactive cost cleanup, they design migrations around AWS-native tools and financial best practices to keep operations efficient from day one.

Here’s how Cloudtech helps control hidden costs:

  • Right-sizing with AWS tools: Uses AWS Compute Optimizer and TCO Calculator to match workloads with optimal EC2 instance types and storage classes, avoiding overprovisioning.
  • Pre-migration assessments: Runs deep analysis via AWS Application Discovery Service to identify unused services, underutilized licenses, or overbuilt environments before migration.
  • Security and compliance guardrails: Configures IAM roles, KMS encryption, and AWS Config rules early, eliminating costly rework in regulated industries.
  • Post-migration cost visibility: Sets up AWS Budgets, Cost Explorer, and tag enforcement to track spend by team, project, or workload.
  • Training for self-sufficiency: Enables internal teams with AWS Skill Builder and sandbox accounts, helping prevent misconfigurations that drive up costs post-migration.

By addressing these areas proactively, Cloudtech helps SMBs migrate with confidence, while ensuring that the cloud remains financially sustainable as the business grows.

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Wrapping up

Cloud migration offers long-term agility, scalability, and access to modern cloud-native capabilities, but only if done right. For SMBs, unmanaged costs can quietly accumulate through missteps like oversized infrastructure, idle resources, or compliance rework.

Controlling these hidden costs isn’t just about cutting spend. It’s about making migration sustainable, measurable, and aligned with business outcomes. That’s why partnering with an AWS Advanced Tier Partner like Cloudtech matters. With AWS-certified expertise and an SMB-first approach, Cloudtech helps businesses avoid cost traps, set up lasting governance, and build cloud environments that deliver value well beyond day one.

Planning your cloud migration? Make every dollar count—Connect with Cloudtech.

FAQs

1. What’s the most common hidden cost SMBs face during cloud migration?

The most common hidden cost is overprovisioned compute resources, where businesses choose larger Amazon EC2 instances than needed “just in case.” This leads to unnecessary recurring charges. Tools like AWS Compute Optimizer and Cloudtech’s sizing assessments help avoid this by baselining actual usage.

2. How can SMBs prevent cost sprawl after migration is complete?

Post-migration, cost sprawl typically occurs from idle or orphaned resources. SMBs can prevent this by implementing automated cleanup scripts, enforcing tagging policies, and using AWS Budgets and Cost Explorer to track usage by environment or team.

3. Does using managed services like Amazon RDS or Redshift help reduce costs?

Managed services can reduce operational overhead and increase efficiency, but only when used correctly. Underutilized managed services (e.g., provisioned Amazon RDS without autoscaling) can inflate costs. SMBs should monitor usage via CloudWatch and consider serverless or on-demand models where appropriate.

4. Are data transfer fees really a problem for small businesses?

Yes, especially if workloads involve frequent cross-region replication or large data exports outside AWS. These egress fees can add up. Solutions include consolidating workloads into a single region, using Amazon CloudFront for caching, and planning data flows before migration.

5. How does Cloudtech help SMBs manage migration costs specifically?

Cloudtech starts with a business-aligned cost assessment, using AWS TCO tools, Compute Optimizer, and Application Discovery Service to plan cost-efficient architectures. Post-migration, they configure budgets, tagging, and resource monitoring to keep costs transparent and controlled.

With AWS, we’ve reduced our root cause analysis time by 80%, allowing us to focus on building better features instead of being bogged down by system failures.
Ashtutosh Yadav
Ashtutosh Yadav
Sr. Data Architect

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