Purpose-Built for UK Jewellery Dealers
Inventory management software for dealers of unique items. Create custom templates to track exactly what matters for each type of stock — hallmarks, serial numbers, gemstone grades, or anything else. Counter, cabinet, fair, and website all read from one stock list. Built by someone who has run the back office of a UK dealing business since 2013.
Inventory
6 items
Art Deco Diamond Ring
JWL-2026-0089
Cartier Tank Watch
WCH-2026-0034
Georgian Silver Candelabra
ANT-2026-0056
Hermès Birkin 25
HBG-2026-0012
Edwardian Sapphire Pendant
JWL-2026-0091
Rolex Datejust 1601
WCH-2026-0035
Jewellery stock rarely repeats itself. One week it is a hallmarked Victorian bracelet from a private seller, the next a modern diamond ring taken in part-exchange. Recording the detail, pricing each piece per channel, and getting the margin scheme right is where the working day tends to go.
A hallmarked gold bracelet needs assay office and fineness mark recorded. A designer handbag needs serial number and authentication details. A vintage watch needs movement type and service history. One rigid set of columns cannot hold all three, so you end up with workarounds in the description box and gaps where the detail should be.
Every selling channel charges different fees and commission. Working out what to list at on Shopify, 1stDibs, or in-person card sales to hit the same profit means recalculating for every item on every platform. One mistake and you sell at a loss.
The Margin Scheme is optional. You can choose it for second-hand jewellery you were not charged VAT on, such as pieces bought from private sellers; precious metals, investment gold and precious stones cannot go on it. Using it means knowing which pieces qualify, applying 1/6 to each margin, and keeping the stock book and invoices the scheme asks for. GemJam records the VAT treatment of each piece, flags unclear cases for your review, and produces the stock book and invoices from those records.
The same ring might be in the cabinet, listed on Shopify, and promised to someone who saw it at a fair. Because there is only ever one of it, every channel has to be corrected by hand the moment it goes — or you sell it twice.
Taken in the order a piece reaches you: describe it, price it, account for the VAT, put it in front of buyers.
Create templates with different fields for each category you sell. A hallmarked jewellery template might track assay office, fineness mark, and date letter. A designer handbag template might track serial number, model, and authentication. You decide what matters.
Enter your listing price once — the amount you’d accept with no fees. GemJam calculates what to list at on each selling channel (Shopify, 1stDibs, in-person card sales) so you hit the same profit after fees. Configure each channel’s fee structure once in settings.
When you log a purchase, GemJam assesses it for the scheme on what the piece is and how you acquired it, not the seller's VAT status alone, and flags it for you to confirm. The VAT is then worked out against the margin on sale. The figures behind your stock book and your VAT return are the same figures, entered once.
Send a piece to Shopify from inside GemJam. Record the sale and your stock and the connected Shopify listing update together, though anywhere not yet connected is still yours to update. eBay integration is in development. Marketplace bridging tools for jewellery and antiques marketplaces such as 1stDibs (Professional and above) are coming soon, so you can bulk-export listings without retyping every piece.
PUR-2026-0042
Hatton Garden Estates · 15 Feb 2026
Subtotal
£8,250.00
VAT
£0.00
Margin Scheme
Total
£8,250.00
Line Items
Art Deco Diamond Ring, c.1925
JWL-2026-0089
£3,450.00
AvailableVictorian Pearl Brooch
JWL-2026-0090
£1,800.00
SoldCartier Tank Watch, 1970s
WCH-2026-0034
£3,000.00
AvailableIf you deal in more than one category, the details that decide a sale change with the category: assay marks on one piece, a reference number on the next. Give each category its own template and every item is asked for the information that actually applies to it.
Create a template with fields for assay office, fineness mark, date letter, sponsor's mark, metal type, purity, and gemstone details. Search and filter your stock by any of these attributes when a customer asks for something specific.
Track model numbers, serial numbers, RRP, material, and what’s included (box, papers, certificate). Use calculated fields to automatically mask serial numbers for public listings while keeping the full number in your records.
Templates can be broad (one for all jewellery) or narrow (one just for VCA Alhambra bracelets). Add text fields, number fields, date fields, select lists, or calculated fields that transform other values. You control the level of detail.
Every item links to its purchase record and the contact you bought from. Track where each piece came from, what you paid, and the chain of ownership — giving buyers the provenance details they expect.
Second-hand jewellery you were not charged VAT on, such as pieces bought from private sellers, can go on the Margin Scheme if you choose to use it; precious metals, investment gold and precious stones cannot. The scheme charges VAT on the profit margin instead of the full selling price, and GemJam works out that VAT piece by piece as you trade.
A VAT treatment recorded for every piece you buy, with unclear cases flagged for your review
VAT charged at 1/6 (16.67%) of the margin on every eligible piece
Produces the Stock Book and invoices from the same records
Xero-compatible export you can forward to Dext
Everything listed is in GemJam now, except items marked coming soon.
What dealers want settled before committing their stock to a new system.
Every item in GemJam has standard fields: title, SKU, acquisition date and price, listing price, status, description, condition, location, category, HS code, and country of origin. Beyond these, you create custom templates with fields tailored to each type of stock. A hallmarked jewellery template might include assay office, fineness mark, date letter, and sponsor’s mark. A designer handbag template might track brand, model, serial number, and authentication details. A vintage watch template might record movement type, case material, and service history. You choose what to track for each category — as broad or as specific as you need.
You enter a listing price for each item — the amount you’d accept if there were no fees or commission. GemJam then calculates the price you’d need to list at on each selling channel (Shopify, 1stDibs, in-person card sales, your own website) to make the same profit after that channel’s fees. You configure the fee structure for each channel once in settings, and GemJam does the maths on every item automatically.
Every purchase in GemJam carries a VAT treatment, and Margin Scheme eligibility sits on each item record for you to set. Eligibility turns on the goods and on how you acquired them: second-hand stock the scheme covers, bought on an invoice that charged you no VAT. Buying from a private individual or a non-VAT-registered seller usually means no VAT was charged, but it is the purchase that decides, not the seller. Sell a scheme piece and GemJam calculates VAT at 1/6 of the profit margin instead of the full selling price. GemJam produces the Stock Book and invoices from the same records.
Yes. You can import items from Shopify, upload a spreadsheet (CSV or Excel), or add items individually. Each piece gets its own record with photos, purchase history, and your custom template fields. The import itself is quick; the time you spend after that depends on how consistent your existing records are.
Yes. GemJam pushes your listings directly to Shopify, including photos, descriptions, and pricing. When an item sells on Shopify, GemJam automatically updates your inventory and records the sale. eBay integration is coming soon. This means you manage everything in one place rather than duplicating work across platforms.
Every piece of jewellery is different, and so is its price. GemJam treats every item as one-of-a-kind with its own purchase price, provenance, and margin. You create custom templates with different fields for each type of stock, so a fine jewellery template tracks hallmarks and gemstone grades while a luxury handbag template tracks brand, model, and condition. GemJam also calculates what to list each item at on every selling channel so you hit your target profit after fees. It handles VAT Margin Scheme calculations natively, pushes listings to Shopify (eBay coming soon), tracks individual item profitability, and produces the Stock Book and invoices from the same records. It was built by someone who has run the back office of a UK dealing business since 2013 and understands the specific challenges.
Watches, antiques, and designer handbags can all sit in the same stock book as your jewellery.
Assay detail, provenance, channel pricing, and margin held against the item rather than scattered across tabs. Join the waiting list for early access.