UM Multistore Sync

Yes. Every store that should be synced needs the app. To connect them, you open the app in one store and then in the other.

You still only pay once: one subscription covers the whole sync group.

With an invite code. You create it in the app in one store and enter it in the app in the other store. The code is valid for 15 minutes and can be used exactly once.

Being able to enter the code means you have admin access to both stores. That is the proof that they belong together. A store can only be in one group.

By SKU only. Leading and trailing spaces and upper or lower case don't matter: sl-123 and SL-123 count as the same SKU. The app never uses product IDs, handles or titles, because the same item has different IDs and handles in different stores.

Matching doesn't write anything. You see the result first: what was matched and what wasn't, each with the reason.

They aren't matched and aren't synced. On the Matching page they appear under "Not matched" with the reason "No SKU set". Add a SKU and start matching again.

The same goes for a SKU that appears twice in the same store: it is deliberately not synced at all, not even in the other stores, until that's resolved.

No. Matching runs when you start it. After adding products or changing SKUs, click "Update matching" on the Matching page. Until then, real-time sync does nothing for a new SKU.

Each matched SKU in your group counts once, no matter how many stores it appears in. A T-shirt in size M with the same SKU in two stores is one variant. Variants that aren't matched don't count.

The current number is shown on the Overview page next to your plan's limit.

No. One subscription covers all stores in the group. If more than one store has a subscription, the highest plan applies. If you open the Plan page in another store, it tells you which store the subscription runs through. You change it from that store.

From 80% of the limit, the Overview page lets you know. Once you're over it, it names the plan that fits.

Syncing doesn't stop. Real-time sync that is already on keeps running, and syncs keep running. You just can't turn real-time sync on again until you're on a plan that fits.

Matching writes nothing. The app only writes once you run a sync or turn on real-time sync. When you turn it on, the app first syncs all inventory using your rule, so real-time sync starts from equal numbers.

You choose the rule beforehand in Settings: "Highest inventory wins", "Lowest inventory wins" or "A specific store wins".

The default is two-way: an inventory change in one store applies to all the others. That's the usual setup to prevent overselling.

One-way only sends changes from a store you choose. Sales in the other stores then don't lower that store. You set the direction in Settings.

You link locations into location links: this location in one store holds the same inventory as that location in the other. Syncing only happens within a location link, and you can have several. If each store has exactly one location, the app links them for you.

The app never changes locations that aren't in a location link. Inactive locations and locations managed by another service can't be linked.

Every update is saved first and processed afterwards. If one is left over, for example after a restart, the app picks it up. If a transfer doesn't go through, the app retries it over twelve hours, with growing gaps between attempts.

If the app itself was unreachable for more than 15 minutes, it starts a sync on its own afterwards for every group with real-time sync on. If a sync finds differences even though real-time sync was running, it brings them back in line and reports it on the Overview page as "Missed real-time changes".

Anything that still failed after all retries is listed on the Overview page under "Needs your attention". Once you've fixed the cause, you queue it again from there.

If more than 20 inventory levels in one store drop to 0 within 10 minutes, the app pauses real-time sync for that store. That looks like an import or an empty store, not like sales. The other stores keep running. Once you've checked, you resume real-time sync from the Overview page.

Syncs have their own brake: a SKU that would drop to 0 even though another store has stock isn't written. If that affects too many SKUs at once, the sync stops without writing anything.

The app doesn't send emails. Problems are shown on the Overview page: a store that can't be reached, paused real-time sync, items that need your attention. If a problem lasts more than 30 minutes, the Overview page points that out.

No customer data and no orders. The app asks for three permissions only: read products, write inventory and read locations.

It stores what syncing needs: the shop's address and Shopify's access token (encrypted), product and variant names, SKUs, locations, inventory quantities, the activity log and your plan. The server is in Germany. The details are in the privacy policy.

The access token is deleted immediately. 48 hours later, Shopify sends the request to delete all of the shop's data. The app then deletes it completely, and the store leaves the group.

If you install the app in that store again, it starts from scratch. You connect it again with a code.