Frequently Asked Questions
Common questions about NumisDex, error coins, and the platform.
What is NumisDex?
NumisDex is a community-driven platform for cataloging, identifying, and validating U.S. coin varieties and errors. With over 72,000 listings, it serves as a comprehensive reference for collectors, dealers, and numismatic enthusiasts.
What are error coins?
Error coins are coins that were produced with mistakes during the minting process. These can include doubled dies, off-center strikes, wrong planchet errors, die cracks, repunched mint marks, and many other types. Error coins are often more valuable than their regular counterparts due to their rarity and collector interest.
How do I identify an error coin?
Start by browsing the NumisDex catalog or using the search to find coins similar to yours. Compare your coin's characteristics against known error types in our Learn section. Look for features like doubling on letters or dates, off-center strikes, unusual planchet material, or die cracks. Our catalog includes images and descriptions to help with identification.
How do I submit a listing to the catalog?
Registered users can submit new error coin or strike type listings through the submission form. Provide clear images (obverse and reverse), a descriptive title, error type classification, and any relevant cross-references. Your submission enters the community vetting process where other members vote to validate the entry.
What is the community vetting process?
When a listing is submitted, it starts at Tier 0 and enters community review. Other users can vote to confirm or reject the listing. As a listing accumulates positive votes, it progresses through tiers (Tier 1 through Tier 4). Higher tiers indicate greater community confidence in the listing's accuracy. Expert users can also provide authoritative overrides.
What is Numiscore and how do tiers work?
Numiscore is your community reputation score earned through participation. You earn points by submitting listings, voting on others' submissions, and contributing to the catalog. Your Numiscore determines your tier level (Novice through Expert), which unlocks additional privileges like increased submission limits and voting weight.
What does an ND catalog code mean?
ND stands for NumisDex. When a listing reaches Verified status through the community vetting process, it receives a unique ND catalog code (e.g., ND-00001). This code serves as a standardized reference identifier for the error variety, similar to how other numismatic references assign catalog numbers.
How do I use the search and filters?
The catalog search supports searching by coin name, year, mint mark, error type, and more. Use the filter panel to narrow results by denomination series, error type, tier status, year range, or value range. The advanced search page provides additional query building capabilities for power users.
Can I track my coin collection on NumisDex?
Yes. The portfolio feature lets you track coins in your collection by adding catalog listings to your personal portfolio. You can create multiple portfolios, import coins via CSV, and optionally share your collection with a public profile link.
What premium features are available?
NumisDex offers tiered subscription plans (Enthusiast, Collector, and Dealer) that unlock additional features such as increased portfolio limits, CSV import/export, ad-free browsing, the Query Builder for advanced searches, higher daily submission limits, and priority support. Visit the pricing page for full details.
Is NumisDex free to use?
Yes. The core catalog, search, community voting, and basic portfolio features are free for all registered users. Premium subscriptions are optional and provide enhanced limits and additional tools for serious collectors and dealers.
Where does the catalog data come from?
The NumisDex catalog combines data from established numismatic reference sources (including legacy imports from well-known variety websites) with community-submitted listings. All data goes through verification processes to maintain accuracy. Legacy imports are clearly marked, and community submissions are vetted through the tiered voting system.
Have a question not answered here? Contact us or visit our Getting Started guide.