Yuwen Chen

About Me

I'm an 8-year Amazon FBA seller with over 14 years of experience in cross-border e-commerce. What started as a single-product listing on Amazon US has grown into a multi-marketplace operation spanning the US, EU, and UK.

In 2024, I built ylishi.tools because I was tired of seeing fellow sellers struggle with the same problems I faced early on — confusing FBA fee structures, opaque EU VAT rules, and PPC campaigns that bled money without clear ROI. Every tool on this site is something I wished existed when I was starting out.

I believe every Amazon seller — whether you're shipping 10 units a day or 10,000 — deserves access to professional-grade tools without paying enterprise prices. That's why every tool on ylishi.tools is free.

Expertise & Credentials

Over the years, I've developed deep expertise across the full Amazon seller stack:

• Amazon FBA Operations
• PPC Campaign Management
• EU VAT & EPR Compliance
• Pan-EU & EFN Strategies
• Product Sourcing & Margins
• Inventory Management
• Amazon DSP Advertising
• Fee Optimization
• IOSS Import VAT
• German LUCID Registration
• Cross-Border Logistics
• Profit Analysis

Tools I've Built

Every tool is free, no sign-up required:

• FBA Calculator — Estimate FBA costs and profits instantly
• EU Tax Calculator — Calculate import duties, VAT, and total landed costs
• PPC Budget Optimizer — Data-driven PPC budget allocation for 2026
• PPC Targeting Guide — Advanced keyword and audience targeting strategies
• PPC vs DSP Comparison — Understand when to use each advertising platform
• Pan-EU vs EFN Guide — Complete comparison for EU expansion
• EU VAT Registration Guide — Cost breakdown by country
• EPR Compliance Guide — Everything you need to know about EPR
• IOSS Import VAT Guide — Simplified EU import VAT explained
• German LUCID Registration — Step-by-step packaging compliance

The Story Behind ylishi.tools

Back in 2018, I made a costly mistake on my Amazon EU expansion. I miscalculated VAT obligations across three countries and lost nearly two months of profit to unexpected tax bills. That's when I realized: there was no single, reliable tool that could help sellers like me understand the true total cost of selling cross-border.

I started building internal calculators for my own use. Other sellers in my network saw them and asked for access. Word spread. By 2024, I decided to open-source all of them as ylishi.tools — a completely free toolkit for Amazon sellers worldwide.

Today, ylishi.tools serves sellers in over 50 countries. Every tool is maintained, updated with the latest Amazon fee schedules, and designed to give you the numbers you need to make profitable decisions.