InvalidBucketName
AWS InvalidBucketName (Invalid Bucket Name) means the specified bucket name is invalid for Amazon S3 naming rules. In Amazon S3, this error returns HTTP 400.
Last reviewed: February 19, 2026|Editorial standard: source-backed technical guidance
What Does Invalid Bucket Name Mean?
When InvalidBucketName is returned, bucket provisioning fails at input validation, so storage-dependent setup steps cannot proceed until a rule-compliant name is generated.
Common Causes
- -Bucket name violates S3 rules (for example invalid length or disallowed characters).
- -Name includes uppercase letters, underscores, or other characters not allowed by S3 DNS-style naming.
- -Name is formatted like an IP address or uses reserved prefixes/suffixes.
- -Automation generates names that start/end with invalid separators or duplicate dots.
How to Fix Invalid Bucket Name
- 1Generate bucket names with a validated naming helper that enforces S3 constraints.
- 2Use lowercase letters, numbers, and allowed separators only.
- 3Reject names that resemble IP addresses or violate reserved naming patterns.
- 4Retry CreateBucket only after producing a rule-compliant candidate name.
Step-by-Step Diagnosis for Invalid Bucket Name
- 1Capture failing bucket name and request ID from the API response.
- 2Run candidate name through automated naming-rule validation in CI and runtime.
- 3Check whether templating logic introduces uppercase, underscores, or invalid delimiters.
- 4Audit environment-specific suffix logic that may break length or reserved-pattern limits.
Schema and Contract Review
- -Parse candidate names against S3 naming contract before CreateBucket (example: general purpose bucket names must be 3 to 63 characters).
- -Inspect generated names for DNS and reserved-pattern compliance (example: names formatted like IPv4 addresses are rejected).
Input Constraint Checks
- -Verify allowed character set and casing (example: only lowercase letters, numbers, periods, and hyphens are valid).
- -Audit formatting edge cases in template output (example: adjacent periods or invalid start/end characters violate bucket rules).
How to Verify the Fix
- -CreateBucket succeeds with the corrected name in the intended region.
- -Follow-up bucket configuration steps complete without naming-related failures.
- -Name validator tests pass for edge cases and generated names.
How to Prevent Recurrence
- -Centralize S3 naming policy in one reusable library across services.
- -Add pre-deploy checks that block invalid bucket names before runtime.
- -Continuously lint generated infrastructure names against S3 constraints.
Pro Tip
- -reserve a deterministic naming prefix per environment and append a GUID segment to prevent both format failures and future global collisions.
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.