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Contact & Seller Support

Spotted a recent marketplace fee revision? Have an idea for a new calculator or reverse margin feature? Send us a note below.

Active Support

Direct Email

Prefer standard email? Reach our technical and fee research team directly:

Reporting a Fee Rate Change?

Marketplaces update schedules frequently. To help us verify and update the calculators quickly, please include:

  • 1.The marketplace name & country region (e.g. eBay UK, Amazon US)
  • 2.The category or fee rule changed (e.g. new $0.40 order fee)
  • 3.An official policy link or announcement date
Average Response Time:24 – 48 Hours
Fee Verification Cycle:Weekly Audits
Support Cost:100% Free

Send Us a Message

Fill out the details below and our team will get back to you promptly.

Frequently Asked Questions

Quick answers to common questions about our platform.

How quickly do you update fees when platforms change rates?

We monitor official seller portal announcements weekly. When an update is announced, our formulas are tested and deployed within 24–48 hours of effective dates.

Can you add a custom calculator for my region's marketplace?

Yes! Send us the marketplace details and link to its published fee schedule. We regularly expand our regional platform coverage based on seller demand.

Is eComFees really 100% free to use?

Yes. All core calculation tools, reverse margin solvers, and category directories are free with no subscription tiers or paywalls.

Do you store my pricing inputs or inventory costs?

No. All math runs strictly inside your local web browser. We never log or send your item pricing, sales figures, or margins to remote servers.