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Terms of Service

Last updated: 18 May 2026 · Effective from: 18 May 2026

1. Agreement

These Terms of Service ("Terms") govern your access to and use of the SellerEngine website (sellerengine.app) and the SellerEngine tools — Sniper Hub, Stock Control, PricePricer, TaxLedger, Sales Hub, and Listing Health (collectively, the "Services"), operated by Polarstar OÜ, an Estonian private limited company located at Tornimäe tn 5, 10145 Tallinn, Estonia ("SellerEngine", "we", "us", or "our").

By creating an account, connecting your Amazon Seller Central or Amazon Ads account, or otherwise using the Services, you ("you" or "Customer") agree to these Terms. If you do not agree, do not use the Services.

2. Eligibility

To use the Services you must:

3. Description of the Services

3.1 What the Services do

The Services let you:

  • Read your Amazon Seller Central data via the Amazon Selling Partner API (orders, FBA inventory, pricing, settlement reports, listings) and your Amazon Ads performance data via the Amazon Advertising API (campaigns, keywords, search terms, reporting).
  • Analyse that data with our heuristics (e.g. PPC waste detection, keyword harvest opportunities, bid optimization, FBA stock coverage, margin-aware price suggestions, VAT export preparation, listing quality monitoring).
  • Execute write actions on Amazon — such as bid changes, negative keywords, harvested keywords, product targets, and price updates — when and only when you explicitly approve the action through the UI.
  • Run a once-per-day read-only sync of Sales Hub aggregated metrics (no write actions), so revenue and unit dashboards reflect the most recent settlement data.

3.2 What the Services do NOT do

  • We do not place orders, send payments, change your bank details, or alter your Amazon account credentials.
  • We do not run automated write actions on Amazon without your explicit per-action consent. The daily Sales Hub sync is strictly read-only.
  • We do not guarantee any specific business outcome (e.g. higher revenue, lower ACoS, better organic ranking, VAT recovery). The Services are a decision-support tool; you remain in control and responsible for the decisions you accept.

4. Your account and authorization

  • You are responsible for keeping your SellerEngine credentials secure and for any activity that happens under your account. Two-factor authentication (TOTP) is enabled by default and cannot be disabled.
  • When you connect your Amazon account via Login with Amazon (LWA), you grant SellerEngine the OAuth scopes necessary to read Seller Central and Advertising data and to execute write actions on your behalf (under your explicit per-action consent). You can revoke this access at any time from your Amazon account or by deleting your SellerEngine account (see Privacy Policy, §7).
  • Refresh tokens are encrypted at rest with AES-256-GCM in our European data store and are never exposed to your browser.
  • You agree not to share your account, transfer it, or let third parties use it on your behalf without our written consent.

5. Acceptable use

You agree NOT to:

  • Use the Services to violate Amazon's policies or applicable law.
  • Reverse engineer, decompile, or attempt to extract the source code of the Services (beyond what local applicable law expressly permits).
  • Scrape, mirror, or systematically download data beyond what the normal use of the Services requires.
  • Interfere with the security or integrity of the Services, including probing, scanning, or testing vulnerabilities without our written consent.
  • Use the Services on behalf of an Amazon account you do not own or are not authorized to operate.
  • Resell or sublicense the Services to third parties without a separate agreement with us.

6. Fees and billing

SellerEngine is offered on a subscription basis. Current published plans:

  • Founder: €69 for a limited period after trial.
  • Monthly: €149/month after trial.
  • Annual: €1,490/year after trial.

Paid subscriptions include a 7-day trial after successful card setup. No subscription charge is made at checkout. The first charge is attempted when the 7-day trial ends unless you cancel or deactivate the subscription before the trial end date.

All prices are exclusive of VAT. EU business customers providing a valid VAT ID are billed under the reverse-charge mechanism per Article 196 of EU Directive 2006/112/EC; non-EU and EU non-business customers are billed with the applicable VAT rate. VAT and tax IDs are collected at checkout via Stripe Tax and shown on invoices.

Billing terms:

  • Subscription fees are billed in advance for the period chosen (monthly or annual) by Stripe Payments Europe Ltd (Ireland) as our payment processor.
  • Fees are non-refundable except where required by applicable law.
  • You authorize us to charge your selected payment method on each renewal until you cancel the subscription via the Customer Portal or by emailing support@sellerengine.app.
  • We may change pricing with 30 days' notice; changes apply at the next renewal.
  • Failed payments may suspend access to live (non-demo) features until the invoice is settled.

7. Intellectual property

All intellectual property in the Services — including the software, algorithms, UI, documentation, and branding — belongs to Polarstar OÜ or its licensors. The Services are licensed, not sold, to you.

Your data remains yours. You retain all rights in the advertising data, business data, and content you input into or generate through the Services. You grant us a limited, non-exclusive license to process that data solely to provide and improve the Services (see Privacy Policy for details).

8. Disclaimers

The Services are provided "as is" and "as available". To the maximum extent permitted by applicable law, SellerEngine disclaims all warranties, whether express or implied, including warranties of merchantability, fitness for a particular purpose, non-infringement, and uninterrupted operation.

Specifically:

  • We do not warrant that the Services will produce any specific advertising, sales, inventory, pricing, tax, or listing-quality result.
  • We do not warrant that the Amazon Selling Partner API or the Amazon Advertising API will be available, accurate, or behave consistently — Amazon controls those APIs and may change rate limits, schemas, or scopes without notice.
  • You acknowledge that automated and semi-automated PPC, pricing, and inventory operations carry inherent risk and that you remain the decision-maker for every action you approve through the UI.

9. Limitation of liability

To the maximum extent permitted by applicable law:

  • SellerEngine's total aggregate liability arising out of or related to these Terms is limited to the fees you paid us in the 12 months preceding the event giving rise to liability, or €100 if higher.
  • We are not liable for indirect, incidental, special, consequential, or punitive damages — including lost profits, lost revenue, lost ad spend, lost goodwill, or loss of data — even if we have been advised of the possibility.
  • Nothing in these Terms limits liability that cannot be limited by applicable law (e.g. liability for fraud, willful misconduct, or mandatory consumer protection rights).

10. Indemnification

You agree to defend, indemnify, and hold harmless Polarstar OÜ, its affiliates, officers, and employees from any claim, demand, loss, or expense (including reasonable legal fees) arising out of your use of the Services in violation of these Terms or applicable law, including Amazon's policies.

11. Termination

  • By you: you may stop using the Services and delete your account at any time via the account settings or by emailing support@sellerengine.app.
  • By us: we may suspend or terminate your access if you materially breach these Terms, abuse the Services, or use them in a way that puts us, other customers, or third parties at risk. Where practicable, we will give notice and an opportunity to cure.
  • Upon termination, sections 7 (IP), 8 (Disclaimers), 9 (Liability), 10 (Indemnification), and 14 (Governing law) survive.

12. Modifications to the Services and these Terms

We may add, change, or remove features at any time. If a change materially reduces functionality or your rights, we will notify you with at least 14 days' notice.

We may update these Terms periodically. Material changes will be notified by email at least 14 days before taking effect. Continued use of the Services after the effective date means you accept the updated Terms.

13. Third-party platforms and subprocessors

The Services rely on third-party platforms and infrastructure providers. Your use of those platforms is governed by their respective terms; you are responsible for complying with them. If a third party suspends, deprecates, or changes their service in a way that impacts SellerEngine, we will do our best to adapt but cannot guarantee uninterrupted functionality.

The platforms we rely on are:

  • Amazon Selling Partner API — orders, FBA inventory, pricing, settlement reports, and listings data; governed by the SP-API Data Protection Policy and the Amazon Services Business Solutions Agreement.
  • Amazon Advertising API — PPC campaigns, keywords, search-term reports, and write actions; governed by the Advertising API License Agreement.
  • Cloudflare Inc. (USA) — edge compute, database (D1), and object storage (R2) under a Data Processing Agreement with Polarstar OÜ.
  • Hetzner Online GmbH (Germany, EU) — dedicated compute for Amazon connection sync, under DPA.
  • Stripe Payments Europe Ltd (Ireland, EU) — billing and payment processing, under DPA. Stripe is also a controller for payment-method and KYC data per its Services Agreement.

A complete and up-to-date subprocessor list is published in the Privacy Policy, §4.

14. Governing law and disputes

These Terms are governed by the laws of Estonia, without regard to its conflict-of-law rules. The exclusive jurisdiction for disputes arising out of or related to these Terms or the Services is the courts of Tallinn, Estonia, unless mandatory consumer protection rules in your country grant you the right to bring suit elsewhere.

15. Miscellaneous

  • Entire agreement: these Terms and the Privacy Policy form the entire agreement between you and SellerEngine regarding the Services.
  • Severability: if any provision is found unenforceable, the remaining provisions stay in effect.
  • No waiver: our failure to enforce a right is not a waiver of that right.
  • Assignment: you may not assign these Terms without our consent. We may assign them in connection with a merger, acquisition, or sale of assets.
  • Notices: notices to you may be sent to the email associated with your account; notices to us must be sent to legal@sellerengine.app.

16. Contact

Questions about these Terms:
Email legal@sellerengine.app
Postal: Polarstar OÜ — Tornimäe tn 5, 10145 Tallinn, Estonia