Inventory software for UK dealers in one-of-a-kind stock: jewellery, watches, handbags, antiques and more
Everything your stock book does — and the VAT looks after itself.
Carry on recording what you buy and what you sell, just as you always have. Because GemJam is built around individual pieces rather than SKUs, it keeps the purchase price, seller and margin on every item, so your VAT margin scheme records stay in order automatically. It holds your whole stock in one place and keeps your Shopify shop in step (with more sales channels on the way), so there's no double-entry and no wondering what's listed or already sold. Built by a former UK dealer who left the trade to solve this full-time. It's your stock and your records; GemJam just does the tedious bits.
49 of 50 founding member spots remaining. Lock in exclusive pricing for life, from just £49/month.
Locked in for life. Only for founding members. See full plans
- Most people hear from us within 2 weeks
- Personal onboarding to get you set up
- Founding members pay from £49/month instead of £75, locked in for life
Your VAT margin scheme records are already there, item by item.
An HMRC VAT Margin Scheme check is focused, specific, and item-by-item. Here is exactly what GemJam keeps for you automatically, as you go:
Purchase price
The exact amount you paid for the item, per item. Not a batch total.
Purchase date
When you acquired it. Not "sometime last spring". A date.
Seller identity
Who you bought it from, and confirmation it was a non-VAT seller eligible for the scheme.
Margin per item
The actual margin calculation: sale price minus purchase price. Not an estimate and not an average.
Because GemJam captures all of this as you go, your records are complete and consistent by default. Should HMRC ever ask, you can produce item-by-item records (purchase price, date, seller, and margin) without a scramble.
The margin scheme is a concession, not a right. Records are the price of admission — and yours are already kept.
How GemJam handles this
Your stock book, kept as a side effect of running your business.
When you record a purchase in GemJam, you capture who you bought from, what you paid and what date. That information is attached to the item permanently. When the item sells, GemJam calculates the margin and the VAT on that margin automatically.
There is no separate step to "do your VAT records." The records are the inventory. The margin-scheme report is generated from the same data you use to manage your stock.
- Purchase price, date, and seller recorded at the point of acquisition
- Margin eligibility tracked per item, including free-acquisition provenance
- Margin calculation at 1/6th applied automatically on sale
- VAT report ready for your accountant — per period, per item, always current
GemJam is inventory management software, not an accountant. It keeps accurate records and calculates margins correctly. What you do with that information is between you and your adviser.
Your VAT return report — always ready
VAT Return Report
Q1 2026 · 1 Jan 2026 – 31 Mar 2026
£4,216.50
VAT due on sales
£1,840.00
VAT reclaimed
£2,376.50
To pay HMRC
MTD Box Values
Every figure in this report is derived from your purchase and sale records. Nothing is entered twice.
The brief we wrote
Every inventory tool was designed for stock that restocks.
Reorder points. Quantity-on-hand. Variant SKUs. None of that maps to a 1920s diamond brooch, a vintage Rolex, or a signed Hermès Kelly. When the item sells, it is gone. There is no reorder. There is no stock level of two.
"Software for stock that doesn't restock."
That's the only brief we wrote when we built GemJam. Every decision since has followed from it.
The UK dealers GemJam's inventory software was built for
Different trades, same problem. Every item is unrepeatable.
Jewellery dealers
Hallmarks, carat, provenance — per piece.
Watch dealers
Movement, reference, box and papers — per piece.
Handbag dealers
Season, hardware, authenticity — per piece.
Antique dealers
Period, origin, condition report — per piece.
Also vintage clothing, collectables, vintage toys, militaria, and anything else where the stock does not restock. If your stock is one-of-one, GemJam fits.
Each piece tells you what it needs recorded.
Every item starts with the same foundation: title, SKU, acquisition date and price, condition, location, category. Beyond that, you build templates with the fields that matter for your stock. A template created once works for every similar piece. Structured fields make search and filtering fast.
A furniture dealer builds templates for tables and chairs. A luxury reseller builds them for handbags, necklaces, rings and bracelets, each with the fields that category demands. Same template designer, different fields.
Hallmarked jewellery template
Example: rings, bracelets, necklaces
- Assay office (London, Birmingham, Edinburgh, Sheffield)
- Fineness mark and metal purity (9ct, 18ct, 925, etc.)
- Date letter and sponsor's mark
- Gemstone type, grade, and weight
- Condition and any restoration notes
Designer handbag template
Example: Hermès, Chanel, Louis Vuitton
- Brand, model, season or year
- Blind stamp year and craftsperson (Hermès)
- Hardware colour (gold, silver, palladium)
- Inclusions: box, dustbag, authentication card, receipt
- Exterior, interior, and hardware condition grades
Templates can be as broad as "all antiques" or as narrow as "Victorian silver caddy spoons". Text, number, date, select-list, and calculated fields. You decide what gets tracked.
Purchase record — attached to the item
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
AvailableBuy it, photograph it, list it on Shopify — in one session.
Photograph the piece on your phone, record the purchase, push it to Shopify. All from one place. No copy-pasting descriptions, no manually re-entering prices, no uploading images three times. Works at fairs, house clearances, and auctions. Wherever you buy.
- Photograph, describe and list in one session, on mobile or desktop
- Capture receipts, certificates, and condition notes at the point of purchase
- Push to Shopify directly, with eBay and more coming soon
- Stock levels sync automatically across channels
Your inventory — one view, every item
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
Keep the spreadsheet for what it's good at
Spreadsheets are genuinely excellent tools. If you want to model your buying strategy for next year, run a scenario on pricing, or produce a bespoke report for a business partner, a spreadsheet is the right choice. It is flexible in ways that purpose-built software never will be.
GemJam is not trying to replace every spreadsheet. It is trying to replace the ones you maintain because there is no better option: the ones you update every time you buy something, the ones with the VAT formula you hope nobody accidentally edits, the one you export to send to your accountant at quarter end.
The spreadsheet is a great modelling tool. It is a poor operational system. GemJam is the operational system. Your spreadsheet stays for the analysis work where it shines.
Straight answers to the questions dealers actually ask
No hedging. No marketing speak.
Every organisation's data is completely isolated from other organisations at the database level using Row Level Security. Within the application, no organisation can access another's data. The founder is stepping back from dealing to focus on GemJam full-time — your success is our business model. We have zero reason to look at your data and every reason to protect it.
GemJam was built by a dealer, not a tech company. If you can use a spreadsheet, you can use GemJam. We'll walk you through setup personally — founding members get one-to-one onboarding to make sure you're comfortable before you're left on your own.
The VAT Margin Scheme is a UK VAT arrangement for dealers in second-hand goods, works of art, antiques and collectors’ items. On a qualifying item you pay VAT on the profit margin (selling price minus purchase price) instead of on the full selling price. An item may be eligible where it belongs to one of those categories and you were charged no VAT when you bought it, which is usually the case with stock from private individuals and house clearances. Precious metals, investment gold and precious stones are excluded, and gov.uk carries the full eligibility rules. You record the treatment against the purchase. GemJam then works out the margin VAT on scheme sales, leaves standard-rated stock on its usual VAT treatment, and produces HMRC-compliant reports from the same records.
Yes. You can import directly from Shopify, upload a spreadsheet, or add items one by one. Each piece gets its own record with photos, provenance, and purchase details. We'll help you get set up during your personal onboarding session.
GemJam does everything your stock book does, then keeps your VAT margin scheme records complete automatically and your sales channels in step — no double-entry, no year-end scramble. It's inventory software built around individual pieces, not SKUs, so the compliance detail is captured as you go.
Founding Member Pricing
Exclusive pricing for the first 50 dealers. Billed monthly. Locked in for life.
Solo
Founding MemberLocked in for life
A forever-home for the independent dealer — never tier-locked by size or volume.
Save £312/year vs standard monthly pricing
- 1 user · 1 integration
- Full inventory management — unlimited items
- Purchase and sales tracking
- VAT Margin Scheme calculations
- Stock Book, Export Register, and VAT Return
- Accounting export (Xero/Dext format)
- Custom templates and custom fields
- AI suggestions: ~100/month (coming soon)
- Email support
Professional
Recommended Founding MemberLocked in for life
For dealers ready to bridge marketplaces, deepen analytics, or add a team.
Save £432/year vs standard monthly pricing
Everything in Solo, plus:
- Up to 3 users with role-based access
- Up to 3 integrations
- Sales Performance report
- Supplier Analytics report
- Inventory Valuation report
- AI suggestions: ~300/month (coming soon)
- Marketplace bridging tools (coming soon)
- Priority support
Business
Founding MemberLocked in for life
For galleries adding white-label, API access, and strategic reporting.
Save £852/year vs standard monthly pricing
Everything in Professional, plus:
- Up to 6 users
- Unlimited integrations
- API access and webhooks
- Price encoding
- Advanced SKU configuration
- Admin tools
- AI suggestions: ~1,000/month (coming soon)
- Marketplace bridging tools (coming soon)
- Dedicated support
Still Copy-Pasting Between Spreadsheets and Shopify?
The first 50 dealers to join get founding member pricing, locked in for life. Once they're gone, they're gone.
Join the Waitlist
Secure your founding member spot today.