One subscription, however many Shopify stores you connect.

One store, and it is always the one that set the arrangement up: the main store whose counts everything else follows, or the store that started sharing its stock. Every other store installs StockUnison free, however many join. One subscription covers the whole setup.

The same cap as for connected stores, but it counts the other stores sharing with you rather than the ones following. So Starter covers your store sharing on its own, or your store plus one more. Growth covers up to six stores sharing together, and Scale is unlimited. Sharing stock inside a single store does need a plan — Starter — because that is a real arrangement doing real work, not a preview.

Checking is. You can install free, let StockUnison read your catalogue and show you exactly which products carry the same SKU and what would change, for as long as you like and at any catalogue size. Going live — the point where counts actually start moving together — needs Starter at $19/month.

A store is live when counts are actually being written to it. A store sitting in preview mode or paused does not count against your plan limit, so you can connect and preview as many stores as you like on any plan, including Free.

Nothing is disconnected and no history is lost. The oldest live connections stay live up to the new limit and any extras drop to preview mode, and the app tells you which ones moved. Shared stock moves as one: if the new plan no longer covers every store sharing, the whole arrangement drops to preview rather than half of it staying live, because stock shared between stores is one thing and half of it is not a smaller version of it.

Through your Shopify invoice, alongside everything else you pay Shopify for. StockUnison never sees or handles your card. Change or cancel from Settings → Plan → Change plan in the main store, which opens Shopify's own billing page.

No. It is a plan you can stay on indefinitely. Matching, preview mode, the activity log and the difference checks all keep working — the free plan simply never writes a count anywhere, so it is also a genuine way to see what would happen to your real catalogue before paying anything.