How to prevent overselling across Amazon and eBay (UK, 2026)

Avoid allocating stock manually per channel where possible. In MaxInvent this is the default — the product has one stock number and every channel sees it. If you're on another platform, look for a shared-stock or total-stock mode rather than static channel allocations. Static split allocation can leave stock stranded.

• Stranded stock ('10 on eBay but Amazon is out') is a direct revenue loss.
• Single-pool means the 'first order to land' wins, which works best when sync is fast and buffers are sensible.

A buffer is stock held back from the channel. If you physically have 100 units and set a 10% buffer, Amazon and eBay see 90. This helps absorb the race-condition window during concurrent sales. Start with 10% for fast-movers, 5% for slow-movers, and model higher buffers for anything selling 20+ units/day.

• Fast-movers (5+ sales/day per channel) need larger buffers because the race window has more collisions.
• Slow-movers (under 1 sale/day) may be able to run at 0% buffer, but check collision risk against your own data.
• MaxInvent recalculates recommended buffers nightly based on the previous 14 days of velocity.

Stock sync every 15 minutes is a sensible baseline for many UK multi-channel sellers. Hourly sync creates a wider race window on fast-moving SKUs. MaxInvent runs stock sync every 15 min by default and can push deltas on dispatch as a backstop.

• Poll-only (periodic push regardless of change) is often more resilient than event-only (push only on change) because it can recover from missed events.
• A strong pattern is hybrid: event-driven push plus a scheduled poll as a backstop.

A 'burst sale' is when a SKU sells faster than your sync cadence. Configure MaxInvent to detect this (e.g. 2 sales in under 60 seconds) and temporarily pause the SKU on non-primary channels while stock propagates. Use thresholds that fit your own marketplace volume.

• Pick a 'primary channel' per SKU — usually whichever has the highest margin or volume.
• On burst, the primary keeps selling; secondaries pause briefly until sync catches up.

Even with buffers and fast sync, the occasional oversell can still happen. Document a clear recovery flow: detect the issue, contact the buyer quickly, offer a suitable resolution, and follow each marketplace's seller guidance for cancellation or refund handling.

• A quick, honest response can reduce the risk of poor feedback or marketplace escalation.
• Use each marketplace's official cancellation and buyer-communication guidance.
• Track oversells as a KPI. If the rate rises above your target, review buffers, sync cadence and affected SKUs.

MaxInvent's Oversell Risk dashboard shows: total oversells in the last 7 days, top offending SKUs, suggested buffer adjustments, and estimated revenue protected by your buffer strategy. Review it every Monday morning. If specific SKUs keep oversell-ing, raise their individual buffer rather than raising the global one.