One buyer per unit, from EOI through reservation and SPA to registration. Crosstable is the governed, shared inventory ledger between a developer and its broker channel — one sale per unit, through stages that expire on schedule, with every step audited.
A developer's sales and commercial team releases a tower's units to a channel of brokers and sells them off-plan — before the building exists. Each unit can be sold exactly once, through a regulated chain from expression of interest to reservation to signed SPA to DLD registration. Launches sell out in hours.
The inventory lives in an Excel "availability sheet" circulated on WhatsApp and PDF, and the double-sell happens not because staff are careless but because two people can confirm the same unit in the same minute. Lead CRM, public listings and developer ERP are all well-served; what still runs on the sheet is the governed developer-to-broker allocation ledger itself. In 2025 Dubai booked roughly 135,000 off-plan deals — exactly the pace at which a point-in-time spreadsheet guarantees double-bookings.
Two agents see the same unit marked "Available" within minutes and both confirm before either writes back — and the sheet has no way to stop the second sale.
A reservation past its SPA-signing window stays "reserved" on the sheet, so the unit never returns to inventory and genuine buyers are turned away.
Who approved a discount below floor price, and why, is a cell that doesn't remember.
The availability sheet circulated to the broker channel on WhatsApp is already stale by the time it lands.
Each unit can carry one active sale, and that sale moves through four ordered stages. The headline is the journey itself: a reservation is only good for a set window, and when a buyer misses the SPA-signing deadline the unit surfaces as overdue and goes back to inventory on an operator's say-so. Refusing the second sale closes exactly the pre-registration gap where two agents sell the same unit — the registry's lock, applied upstream, where the danger is.
Crosstable applies the registry's one-buyer rule upstream, where the danger actually lives — before registration, off a stale availability sheet.
Each floor renders as a spine of units, floors stacked penthouse-at-top — the physical stack board every sales office prints, coloured by live status.
EOI, reservation, SPA and registration each need their own proof to advance — a broker reference, a token receipt, an SPA number, an Oqood number.
Pre-handover assignment ("flipping") moves the sale to a new buyer, keeping the full paper trail — and only once a minimum has been paid.
Pre-launch expressions of interest form a dated queue on the scarce high-floor, sea-view stock.
Crosstable enforces one buyer per unit through the stages above. The numbers a developer will probe are settings — and each one says whether it's statutory or yours to choose.
The SPA-signing window and booking-deposit percentage — both per-developer, not statutory; Crosstable ships defaults and says so.
The buyer-default retention sliding scale, as a refund calculator for finance rather than an allocation rule.
Payment-plan schedules and escrow milestones that must be met before a sale moves on.
KYC / AML per party, versioned price-books, and proper handling of joint ownership and its shares.
Jurisdiction labels — Dubai RERA / DLD today, with UK exchange / completion and India RERA following the same shape.