Bucket Types

IONOS S3 Object Storage allows users to create the following two types of buckets:

1. Contract-owned buckets

2. User-owned buckets

Each bucket type has a different feature set to cater to your business needs. For more information, see Feature comparison.

Note: Starting from May 30, 2024, all the newly launched S3 Endpoints (S3 regions) will use a contract owner as a bucket owner. You can still create user-owned buckets using specific endpoints, but this shift toward a contract-owned bucket model will be the primary focus for future Object Storage updates.

Contract-owned buckets

This bucket type is recommended for users within a single organization. Contract-owned buckets are the new bucket types supported in the Object Storage starting May 30, 2024.

Following are the key highlights of this bucket type:

  • The contract owner is the bucket owner of all the contract buckets. The contract owner or an administrator can create and manage buckets by default and define permissions in the Bucket Policy settings for other users to manage the buckets.

  • Every user in the contract can view the list of all buckets within their contract, even if they do not have permission to access the content.

  • Only the contract owner or an administrator can grant users access to view the bucket objects or manage these buckets.

You can create contract-owned buckets only in the following S3 region:

Data CenterS3 Region

Berlin, Germany



  • Currently, cross-regional bucket replication is not possible for contract-owned buckets since this bucket type is supported only in the eu-central-3 region.

  • Logging bucket setting is not supported at the moment.

User-owned buckets

This bucket type is recommended if the users of the contract are separate entities and does not require viewing or accessing buckets of other users in the contract. The bucket type supported before the launch of contract-owned buckets is now termed user-owned buckets.

Every contract user independently owns their buckets and has the autonomy to create and manage them without seeking approval from the contract owner. A combined list of all user-owned buckets under the contract is not available, and the contract owner must individually check the bucket list of the users to view the buckets a user owns.

Users under the contract can only have visibility to their buckets, with no access to other user's bucket lists in the contract.

You can create user-owned buckets only in the following S3 regions:

Data CenterS3 Region

Frankfurt, Germany


Berlin, Germany


Logroño, Spain


Feature comparison

The user-owned bucket and contract-owned bucket offer a wide range of S3 operations with the following differences in their feature set:

FeaturesContract-owned bucketsUser-owned buckets

Bucket ACL

Use to share access to other contracts. To share access with users from the same contract, use Bucket Policy.

Use to share access between users of the contract and to other contracts.

Bucket Access Logging

Not supported


Bucket Replication

Not supported as contract-owned buckets are currently supported only in the eu-central-3 region. You can also replicate user-owned buckets to contract-owned buckets in the eu-central-3 S3 region. This function is supported only through the API.

Supports replication within user-owned buckets of the same user and as well as replication to contract-owned buckets.

Identity and Access Management (IAM)

No, available in the near future.

Not supported

IONOS S3 Select


Not supported

Redirects for Static Website Hosting


Not supported

Free data transfer to VMs within the same region


Not supported

For information on supported API functions for these bucket types, see S3 API Compatibility.

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