InstanceLimitExceeded
AWS InstanceLimitExceeded means your account reached the allowed running On-Demand capacity quota for the requested instance scope. This is a quota-capacity limit, not an API request-rate throttling error.
Last reviewed: February 20, 2026|Editorial standard: source-backed technical guidance
What Does Instance Limit Exceeded Mean?
EC2 rejected the launch because your account quota for the requested On-Demand capacity scope is exhausted, so retries without additional quota headroom will keep failing.
Common Causes
- -EC2 On-Demand vCPU quota for the relevant instance family/class is exhausted in that region.
- -Recent scaling event increased running instances without corresponding quota headroom.
- -Launch plan requests instance types whose vCPU demand exceeds remaining quota.
- -Quota increase requests were not approved before scale-out or migration cutover.
How to Fix Instance Limit Exceeded
- 1Check EC2 Service Quotas for running On-Demand capacity in the target region.
- 2Calculate requested vCPU/instance impact versus current running usage.
- 3Reduce requested capacity, switch instance mix, or stop/terminate non-critical instances.
- 4Submit and track quota increase before retrying production scale events.
Step-by-Step Diagnosis for Instance Limit Exceeded
- 1Capture exact EC2 launch error code, instance type, region, and request ID.
- 2Review EC2 On-Demand quota values and current running usage in Service Quotas.
- 3Map requested instance type to vCPU consumption and compare against available headroom.
- 4Inspect Auto Scaling and deployment plans for sudden quota-crossing launch bursts.
EC2 Quota and Launch Budget Review
- -Profile requested vCPU and instance mix versus account quotas (example: On-Demand vCPU quota exhausted during scale-out).
- -Inspect launch plans against remaining quota headroom before execution (example: migration batch requests 2x available vCPU in one wave).
Quota Governance and Scale Planning
- -Audit autoscaling guardrails and admission checks (example: ASG target jumps beyond approved quota after policy update).
- -Validate quota increase lifecycle before planned launches (example: cutover scheduled before quota request approval completes).
How to Verify the Fix
- -Re-run the launch path and confirm InstanceLimitExceeded is no longer returned.
- -Validate running-capacity headroom remains positive after deployment.
- -Confirm autoscaling events complete without quota-limit launch failures.
How to Prevent Recurrence
- -Add quota-aware admission checks before launch and scale workflows.
- -Continuously monitor EC2 quota utilization and alert on low headroom.
- -Pre-request quota increases ahead of planned growth or region expansions.
Pro Tip
- -persist launch-template version, request ID, and resolved AMI and subnet set in telemetry so EC2 failures can be reproduced exactly.
Decision Support
Compare Guide
429 Too Many Requests vs 503 Service Unavailable
Use 429 for caller-specific throttling and 503 for service-wide outages, so retry behavior, escalation paths, and incident ownership stay correct.
Compare Guide
AWS ThrottlingException vs GCP RESOURCE_EXHAUSTED
Compare AWS ThrottlingException and GCP RESOURCE_EXHAUSTED to separate rate limiting from quota/resource exhaustion and choose the remediation path.
Playbook
Rate Limit Recovery Playbook (429 / ThrottlingException / RESOURCE_EXHAUSTED)
Use this playbook to separate transient throttling from hard quota exhaustion and apply retry, traffic-shaping, and quota-capacity fixes safely.
Official References
Provider Context
This guidance is specific to AWS services. Always validate implementation details against official provider documentation before deploying to production.