InvalidParameter
AWS InvalidParameter means one or more request parameters fail service validation for the target operation. Most services return this family as HTTP 400.
Last reviewed: February 10, 2026|Editorial standard: source-backed technical guidance
What Does Invalid Parameter Mean?
When InvalidParameter appears, AWS rejects the request before execution, so no resource mutation occurs and workflow steps halt until the parameter contract is corrected.
Common Causes
- -A parameter value violates allowed pattern, range, enum, or length constraints.
- -Two or more parameters are individually valid but invalid together for this operation.
- -Resource identifiers (ARN/ID/name) are malformed or invalid for the selected API context.
- -SDK defaults or custom serializers inject unintended values into the final request.
How to Fix Invalid Parameter
- 1Read the service error text and correct the first named parameter before broader edits.
- 2Validate each supplied field against the exact API operation constraints.
- 3Reproduce with a minimal valid request, then add optional fields incrementally.
- 4Update SDK/service models if request shape or enum definitions changed upstream.
Step-by-Step Diagnosis for Invalid Parameter
- 1Capture request ID, full error text, and serialized payload for the failing call.
- 2Compare payload against official API examples and documented constraints.
- 3Inspect templating and environment substitution for malformed runtime values.
- 4Add boundary and invalid-combination tests for this operation in CI.
Schema and Contract Review
- -Parse the exact operation contract and required field set before dispatch (example: EC2 rejects a subnet/security-group pair from different VPCs as InvalidParameter).
- -Inspect serialized request output against the current API model to catch stale client shapes (example: an older SDK emits an unsupported field variant).
Input Constraint Checks
- -Verify format and scope constraints for each argument (example: provide full IDs like
sg-...andsubnet-..., not display names). - -Audit cross-parameter dependencies and mutually exclusive options (example: an option that requires a paired parameter fails when only one side is set).
How to Verify the Fix
- -Replay the same operation and confirm InvalidParameter no longer occurs.
- -Validate response semantics to ensure intended behavior is preserved.
- -Check logs for nearby errors such as InvalidParameterValue or ValidationException.
How to Prevent Recurrence
- -Use typed request builders and shared validators for high-impact AWS operations.
- -Enforce contract tests against real service APIs in pre-release pipelines.
- -Block deployments when parameter-schema regression checks fail.
Pro Tip
- -store normalized request payload hashes per API action and diff them across releases to detect silent serializer drift before production.
Decision Support
Compare Guide
HTTP 400 vs 422: Bad Request vs Unprocessable Content
Fix API payload issues faster by using 400 for malformed syntax and 422 for semantic validation failures, so clients correct format before business rules.
Playbook
CORS Error Fix Playbook (Preflight / Origin / Credentials)
Use this playbook to separate browser-enforced cross-origin policy failures from server-side CORS header and route defects and apply strict origin and credential controls safely.
Playbook
Validation Failure Playbook (400 / 422 / INVALID_ARGUMENT)
Use this playbook to separate malformed-request failures from semantic validation failures, then fix request contracts without broad server-side bypasses.
Official References
Provider Context
This guidance is specific to AWS services. Always validate implementation details against official provider documentation before deploying to production.