What are your stamps
really worth?
Condition is everything in philately — margins, gum and faults can move a stamp from pounds to thousands. Assay benchmarks catalogue values against realised sales for a fair, honest number.
How to value stamps
For stamps, condition dominates: centring, complete margins, original never-hinged gum and the absence of faults separate a valuable example from a common one.
Then rarity (issue, errors, varieties) and catalogue standing (blended sold-comp data from eBay and reference databases, Scott) set the benchmark, with realised auction prices grounding it in reality.
Assay reads catalogue values against actual sold prices, so your estimate reflects what the market pays — not just the list price for a flawless example.
Condition
Margins, centring and faults swing value dramatically.
Gum & hinging
Never-hinged mint commands a clear premium.
Rarity & errors
Scarce issues and varieties carry the biggest premiums.
Catalogue vs realised
Catalogue sets the benchmark; sold prices ground it.
Record stamps sales
| Item | Price | Why |
|---|---|---|
| British Guiana 1c Magenta | $8.3M+ | The world's most famous rarity |
| 1840 1d Black (fine) | up to £250 | Margins and condition decide the band |
| Inverted error | $100k+ | Printing errors are the blue-chip of stamps |
Public auction results, shown to illustrate the value drivers Assay blends into every valuation. Not investment advice.
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Stamps valuation FAQ
On condition first — margins, gum and faults — then rarity and catalogue standing, grounded by realised sales. Assay blends blended sold-comp data from eBay and reference databases/Scott benchmarks with sold prices for an honest estimate.
An identical stamp can be worth ten times more with four complete margins and original gum than a creased, off-centre copy. Assay lets you factor condition into the estimate.
The British Guiana 1c Magenta has sold for over $8M — a single surviving example, showing how rarity dwarfs catalogue value.
Yes — one-tap, escrow-protected listings with provenance and seller checks throughout.
Free valuations are included daily, with unlimited valuations and tracking on Pro.
Verified data sources
The authoritative pricing references Assay blends and links to for stamps — so every valuation is traceable.
Independent third-party sources, linked for verification. Trademarks belong to their respective owners; Assay is not affiliated unless stated.
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