Built to Help UK Sellers Make Better Decisions.
SellerStack is an independent resource for UK online sellers and resellers, combining practical guides, free calculators and connected resources to make sourcing, pricing, selling and business decisions easier to understand.
Online Selling Decisions Are More Connected Than They Look
A sourcing decision affects your buying cost. Your buying cost affects your pricing. Pricing affects margin. Marketplace choice changes fees and fulfilment. Shipping changes the final profit. Records help you understand what actually happened.
Information Is Fragmented
Marketplace policies, fee structures, shipping options, tax information and seller tools often live in different places.
Revenue Can Hide Weak Decisions
A product can sell and still produce a poor return once stock, fees, fulfilment and other costs are considered.
Sellers Need Context, Not Just Numbers
A calculator can estimate a result, but understanding the assumptions and the wider selling decision matters too.
SellerStack Connects the Pieces
Our aim is to connect practical guidance, calculations and next steps so useful information does not sit in isolation.
Learn. Calculate. Compare. Decide.
SellerStack is designed around decisions rather than isolated articles. Start with the question you are trying to answer, then move between guidance, tools and related resources.
Learn
Understand marketplace rules, pricing principles, sourcing, fulfilment and seller workflows.
Calculate
Test the numbers behind buying price, selling price, profit, ROI, fees, shipping and other decisions.
Compare
Compare marketplaces, fulfilment choices, costs and practical trade-offs before committing.
Decide
Use the information and estimates together to choose the next useful action.
Practical Resources for the Decisions Sellers Actually Face
SellerStack covers the complete selling journey rather than focusing on one marketplace or one type of reseller.
Seller Guides
Practical guidance covering marketplaces, sourcing, pricing, listings, shipping and business topics.
Explore Guides → 🧮Free Calculators & Tools
Decision tools for profit, pricing, ROI, marketplace fees, sourcing, shipping and UK seller business topics.
Explore Tools → 🛍️Marketplace Resources
Guides and tools covering eBay, Amazon, Vinted, Depop, Etsy, TikTok Shop and other selling routes.
Explore Marketplaces → 🛒Sourcing & Stock
Research demand, buying limits and potential returns before committing money to inventory.
Explore Sourcing → 📦Shipping & Fulfilment
Compare shipping, understand parcel requirements and build more reliable fulfilment workflows.
Explore Shipping → 🧾Tax, Records & Business
Understand HMRC topics, VAT, marketplace reporting, record-keeping and the numbers behind the business.
Explore Business Resources →Estimates Should Help You Think — Not Pretend to Predict
SellerStack calculators are planning tools. Their results depend on the information entered, the assumptions used and the fee or calculation structure available when the tool was last reviewed.
Marketplace fees, seller programmes, postage costs and individual circumstances can vary. Important decisions should be checked against current marketplace information and your own actual costs.
Explore Free Calculators →Better information does not remove uncertainty. It helps you make a more informed decision.
Use realistic inputs rather than best-case assumptions.
Check current marketplace fees before important decisions.
Treat worked examples as explanations, not guarantees.
Accuracy, Context and Clear Limitations
Marketplace fees, policies, fulfilment programmes, software features and UK seller rules change. SellerStack aims to handle changing information carefully rather than present every figure as permanent.
Primary Sources First
For fees, policies, thresholds and official rules, we prefer information published by the organisation responsible where practical.
Time-Sensitive Information
Important guides may include review or update dates so readers can see when changing information was last checked.
Estimates Are Labelled
Calculator assumptions and worked examples are intended to help with planning, not guarantee a financial result.
Corrections Matter
When meaningful outdated or inaccurate information is identified, we aim to correct it when practical.
Recommendations Should Serve the Seller First
SellerStack is an independent resource and is not operated by the marketplaces, software companies, couriers or other brands discussed across the site.
Platform Neutral
No marketplace is treated as the right choice for every product or every seller.
Affiliate Transparency
SellerStack may earn revenue from selected affiliate partnerships and referrals.
Commercial Relationships Do Not Decide the Conclusion
Free, non-affiliate and marketplace-native options can still be recommended when they are the better fit.
Start Where You Are
You do not need a warehouse, thousands of listings or a full-time business to make better selling decisions.
New Sellers
Learn how reselling works without needing to master everything before making your first sale.
Casual & Side-Income Sellers
Improve sourcing, pricing, marketplace choice and record-keeping as selling becomes more regular.
Established Resellers
Compare workflows, costs and tools as volume and operational complexity increase.
Multi-Platform Sellers
Connect decisions across marketplaces rather than treating each selling channel in isolation.
Start With the Decision in Front of You
You do not need to read everything. Choose the part of selling you are working on now and follow the connected path from there.
Help Us Keep SellerStack Useful
If you notice an outdated fee, policy, broken link or factual issue, send us the page URL and the information you believe needs reviewing.