Scott Catalog Number Lookup App for Stamps
Look up a stamp's Scott catalog number by photographing it with an iPhone app — and get a quick visible-condition value estimate before deciding to sell or hold.
Primary Search Intent
scott catalog number lookup app
Related queries
Key takeaways
- Scott catalog numbers are the lingua franca of US and many international philatelic markets — having one in hand makes any subsequent dealer or auction conversation faster.
- Catalog value is not market value; a 'Scott $40' stamp commonly sells at 20–40% of catalog depending on condition and demand.
- Centering, gum, and cancellation are the three visible factors that move a stamp between grade tiers and value brackets.
Quick Answer
[Stamp Identifier](https://apps.apple.com/us/app/stamp-identifier-instant/id6761888665) is a free GradFlowLab iOS app that photographs a postage stamp, returns the most likely Scott catalog number with a confidence rating, and gives a quick visible-condition value estimate.
What a Scott Number Is
The Scott Standard Postage Stamp Catalogue assigns a unique identifier to every distinct postage stamp issue. In the US market it is the dominant reference; in many international markets it is one of the dominant references alongside Stanley Gibbons (UK-centric), Michel (Germany-centric), and Yvert (France-centric).
Having the Scott number in hand means:
- You can search dealer inventories and auction archives in one click
- You can ask the right valuation question instead of "what is this old stamp worth?"
- You can sort an inherited collection in an hour instead of an evening
How to Photograph a Stamp for Best Results
- Daylight, diffuse — direct sun creates glare on gummed stamps; a window with sheer curtain is ideal
- Plain dark background — black paper for pale stamps, white for dark stamps
- Camera flat, stamp flat — both parallel to each other
- Fill the frame — get close enough that the stamp uses 70%+ of the image
- Capture the perforations — perforation gauge is part of identification on many issues
For folded, damaged, or partially attached stamps, photograph both sides and let the app pick the better view.
What the App Returns
- Likely Scott number with confidence rating
- Country and year of issue
- Catalog value range based on the Scott listing
- Visible-condition adjustment based on centering, cancellation visibility, and surface
- Similar issues that are commonly confused (color shades, perforation varieties)
Estimating Value Honestly
Catalog value is a reference price, not a market price. As a rough rule of thumb for common material:
- Common used stamps: 10–30% of catalog
- Common mint with original gum: 30–60% of catalog
- Scarce/popular issues: 60–100% of catalog or above
The app shows the catalog value and an honest visible-condition haircut. For a high-value stamp it will recommend a formal expertization — the catalog is a starting reference, not an appraisal.
Pricing
Free. The identification and basic catalog value are on the free tier.
Try It
Get [Stamp Identifier on the App Store](https://apps.apple.com/us/app/stamp-identifier-instant/id6761888665). Pick the most unrecognizable stamp in your inherited collection or shoebox album, photograph it in daylight, and see how the catalog number plus visible-condition estimate changes what you would have done next.
Frequently asked questions
What is a Scott catalog number, in one sentence?
An identifier from the Scott Standard Postage Stamp Catalogue that uniquely names a specific stamp issue, used as the de facto reference number by US dealers, auctioneers, and collector communities.
Will the app give me what the stamp is worth?
It gives a visible-condition estimate based on Scott catalog value adjusted for what the photo shows about centering, cancellation, and surface. Final realized prices in real sales typically run 20–60% of catalog for common material, much closer to or above catalog for rare items.
Does it work for non-US stamps?
The model identifies many international issues, with US, UK, German, Japanese, and French stamps having the strongest coverage. Less-collected origins return lower confidence ratings, which the app surfaces honestly.