Terms of service
Last updated: 12 July 2026
1. Overview
Welcome to zerrro.
The terms "we", "us", and "our" refer to:
zerrro
Metzinger Klein Linsenmeier GbR
We operate this online store and website, including all information, content, tools, products, and services available through this site — including our AI-assisted audio mastering service ("ZERRRO Mastering") — (collectively, the "Services").
These Terms of Service ("Terms") govern your access to and use of our Services.
By visiting our website, purchasing products from us, and/or using ZERRRO Mastering, you agree to be bound by these Terms and our Privacy Policy.
If you do not agree to these Terms, please do not use our Services.
2. Access and Account
By using our Services, you confirm that you are at least the age of majority in your country of residence.
You agree to provide accurate, current, and complete information for all purchases and communications.
You are responsible for maintaining the confidentiality of your account credentials and for all activities carried out under your account.
3. Products and Digital Delivery
Our store offers digital products (e.g. sample packs and software plugins) delivered by download, as well as digital services (in particular ZERRRO Mastering, see Section 4).
After successful payment, access to digital content is provided immediately via download links or digital delivery by email.
No physical goods are shipped.
We strive to present products as accurately as possible; however, minor deviations may occur due to technical or display-related differences.
We reserve the right to modify, replace, or discontinue products at any time without prior notice.
3a. Territorial Restrictions
Due to legal and insurance restrictions, certain software products offered in our store — in particular plugins and executable software — are not available for purchase by customers whose place of residence or habitual location is in:
- the United States of America (including its overseas territories), or
- Canada
Other digital products and services, such as sample packs, audio content, and ZERRRO Mastering, may be available in these territories unless otherwise stated on the respective product page.
We take reasonable technical measures to prevent the purchase of restricted software products from excluded territories.
If, despite these measures, an order for a restricted software product is placed from an excluded territory, we reserve the right to cancel the order and revoke access to the software. Any payments already made will be refunded without undue delay.
4. ZERRRO Mastering (AI Mastering Service)
ZERRRO Mastering is an online service that processes audio files ("premasters") you upload and produces mastered versions using automated, AI-assisted analysis and audio processing.
4.1 Beta status. The service is currently offered as a beta version. It is under active development and may contain errors, be temporarily unavailable, or change in features and scope at any time. During the beta, we record how the tool is used — including your settings, actions, and uploaded audio files — to identify and fix issues. Details are set out in our Privacy Policy; your consent is requested when you first use the tool.
4.2 Your content. You retain all rights to the audio you upload and to the resulting masters. By uploading audio, you grant us a limited, non-exclusive license to store, process, analyze, and technically reproduce your files solely to the extent necessary to provide the Services (including creating previews, masters, and revisions). We claim no ownership of your music. This license ends when your files are deleted from our systems.
4.3 Your responsibility for uploaded content. You warrant that you hold all rights necessary to upload and process the audio you submit, and that your content does not infringe the rights of third parties (including copyright, related rights, and personality rights) or violate applicable law. You indemnify us against third-party claims arising from a breach of this warranty. You must not upload unlawful content.
4.4 AI processing. Mastering decisions are made in part by automated systems, including third-party AI providers. For this purpose, technical measurement data derived from your audio (e.g. frequency and loudness analysis) and any text instructions you enter are processed by such providers. Your audio files themselves are not transmitted to AI providers. Mastering results are inherently a matter of technical processing and artistic taste; we do not guarantee that a master will meet your subjective expectations. You can audition previews free of charge before using a credit.
4.5 Storage and backups. Uploaded files and generated masters are stored temporarily to provide the service. Files uploaded without an account (guest uploads) are automatically deleted after approximately 24 hours. We may delete uploaded files and generated masters after a reasonable period; download your masters promptly. The service is not a backup or archival service — always retain your own copies of your original files.
4.6 Fair use. We may apply reasonable technical limits (e.g. file size, number of masterings per time period) to keep the service stable for all users.
5. Mastering Credits
Downloads of finished masters require credits, which can be purchased in our store.
- One credit entitles you to the final master of one track, including the revisions offered within the same mastering session.
- Credits are linked to your customer account, are non-transferable, and cannot be redeemed for cash (statutory rights remain unaffected).
- Credits are valid for three years from the end of the year in which they were purchased.
- During the beta phase, downloads may be temporarily offered free of charge; this constitutes a voluntary benefit and does not create a claim to future free services.
6. Prices and VAT
All prices are final prices and displayed in the currency selected at the top of the main page, unless stated otherwise.
In accordance with § 19 of the German Value Added Tax Act (UStG), we do not charge VAT (small business regulation).
Prices may be changed at any time.
Payment must be completed in full before access to digital content or credits is granted.
7. Orders and Payment
By placing an order, you submit a binding offer to purchase the selected product.
The contract is concluded once payment has been successfully processed and the order confirmation is issued.
You agree to provide accurate billing and payment information.
Payment processing is carried out via Shopify Payments, PayPal, or other payment providers integrated into our platform.
We are not responsible for errors or disruptions caused by third-party payment providers.
8. Digital Content, Right of Withdrawal / Refunds
Our products are digital content and digital services.
Consumers residing in the European Union generally have a statutory right of withdrawal of 14 days from the conclusion of the contract.
For digital content delivered by download (e.g. sample packs), the right of withdrawal expires once performance has begun after you have expressly agreed that execution begins before the end of the withdrawal period and confirmed your knowledge that you thereby lose your right of withdrawal. This consent is obtained during checkout. Delivery begins immediately after completion of the order.
For mastering credits, the right of withdrawal applies to unused credits within the statutory period. Once you redeem a credit and the mastered file is made available for download with your express prior consent and acknowledgment, the right of withdrawal for the redeemed service expires.
Further details regarding the right of withdrawal and refunds can be found in our Refund Policy / Right of Withdrawal page.
9. License and Usage Rights (Sample Packs)
Upon purchase of a sample pack, you are granted a non-exclusive, non-transferable, worldwide license to use the included sounds and samples in your own music productions, both commercially and non-commercially.
You may not:
- redistribute, resell, sublicense, or share the samples in isolation or as part of another sample pack or sound library;
- upload or make the raw samples publicly available for download;
- claim ownership or authorship of the individual samples.
Attribution to zerrro is appreciated but not required.
Masters created with ZERRRO Mastering from your own audio belong to you (see Section 4.2); no additional license from us is required to use them.
All rights not expressly granted remain with zerrro – Metzinger Klein Linsenmeier GbR.
10. Intellectual Property
All content available on this website — including text, audio, graphics, logos, product descriptions, software, and digital files — is the property of zerrro – Metzinger Klein Linsenmeier GbR or its licensors and is protected by applicable copyright and intellectual property laws. This does not apply to audio you upload or masters created from it (see Section 4.2).
Any unauthorized use may violate copyright, trademark, or other applicable laws.
11. Disclaimer of Warranties
Our Services and digital products are provided "as is" and "as available", without warranties of any kind, whether express or implied.
We do not guarantee uninterrupted availability, error-free operation, or compatibility with specific software, systems, or digital audio workstations. This applies in particular to the beta version of ZERRRO Mastering. The artistic quality of a mastering result is subjective; free previews are available before a credit is used.
Mandatory statutory rights remain unaffected.
12. Limitation of Liability
We shall be liable without limitation for intent and gross negligence, as well as for damages resulting from injury to life, body, or health.
In cases of slight negligence, we shall only be liable for the breach of essential contractual obligations (cardinal obligations).
In such cases, liability is limited to the typical, foreseeable damage.
We are not liable for the loss of uploaded files or generated masters where you have failed to retain your own copies of your original files (see Section 4.5), except where the loss is attributable to us under the above principles.
Any further liability is excluded to the extent permitted by law.
13. Governing Law and Jurisdiction
These Terms are governed by the laws of the Federal Republic of Germany, excluding the UN Convention on Contracts for the International Sale of Goods (CISG).
If you are a consumer residing in the European Union, mandatory consumer protection provisions of your country of residence remain applicable.
The courts of Saarbrücken, Germany, shall have jurisdiction unless mandatory consumer protection law provides otherwise.
14. Online Dispute Resolution
The European Commission provides an online dispute resolution (ODR) platform:
We are not obliged or willing to participate in dispute resolution proceedings before a consumer arbitration board.
15. Changes to These Terms
You can review the most current version of these Terms at any time on this page.
We reserve the right to update or modify these Terms.
Changes take effect upon publication on our website. Continued use of the Services constitutes acceptance of the updated Terms.
16. Contact Information
Questions about these Terms may be sent to:
Email: info@zerrromusic.com