Turn on Enable Offline Mode in Store Config → Application Settings before an outage: the browser caches an offline sales screen plus your items and customers, you keep ringing cash and manual-tender sales, and queued sales sync — automatically or by button — when you're back online.

An internet outage doesn't have to stop the line. With offline mode on, each register's browser keeps a cached copy of an offline sales screen, your items and your customers, so you can keep ringing sales and sync them once the connection comes back.

The one rule: offline mode must be set up before the outage. A register device that has never loaded the sales screen while online has nothing cached to fall back on.

This article describes the classic sale screen. A register set to Touch UI has its own offline behaviour, with Offline Mode shown on the screen and Sync Offline Sales / Edit Offline Sales buttons in the action bar — see the Touch UI register.

Turn on offline mode

1. Sign in as an admin and go to Store Config → Application Settings.
2. Tick Enable Offline Mode. This also ticks Require https for program — a secure connection is required for offline caching to work, and cloud stores already run over HTTPS.
3. Decide on Auto Sync Offline Sales When Back Online — ticked, queued sales upload themselves as soon as an online sales screen loads; unticked, you sync manually with a button.
4. Set Offline Mode Sync Cycle Time (Hour) — how often the cached data refreshes, from 1 to 48 hours. The default is 24.
5. Click Save.

The settings reference for this Store Config tab is in store configuration basics.

Prime each register device

Caching happens in the browser, per device, so every register needs a one-time visit while online:

1. On the register device, open the sales screen.
2. Leave it open for a few minutes the first time. Two things load in the background: a service worker caches the offline sales page and its assets, and a background worker downloads your items (with their modifiers and variations) and customers into browser storage, 100 records at a time.
3. That's it. The cache then refreshes itself once per sync cycle for as long as the browser is open and someone is signed in — you don't repeat this unless the device or browser changes.

Make this part of commissioning any new register device: enable offline mode, load the sales screen once, done. Offline readiness is a five-minute job while the internet is up and an impossible one once it's down.

Ring sales during an outage

When the connection drops and someone visits your store URL, the cached offline sales screen loads instead, with a banner: "You are offline and can process transactions in a limited way until you come back online."

On the offline screen you can:

• Search cached items by name and add them to the sale, with quantity, unit price and tax shown per line.
• Attach a cached customer by name or account number.
• Take payments with Cash, Check, Debit, Credit, and any custom payment types — as manual records. Card entries here are bookkeeping only: no integrated terminal runs without the network, so a "Credit" line records that a card was taken, and the integrated flow in taking card payments is for when you're back up.
• Click Complete Sale. The sale is queued in the browser with an offline token that identifies it until it reaches the server.

The offline screen is a simplified register: expect item lookup, customers, and payments — not price rules, integrated hardware, or live stock levels.

Sync when the connection returns

Once the register is back online, open the sales screen:

• With Auto Sync Offline Sales When Back Online ticked, queued sales upload immediately.
• Otherwise a Sync Offline Sales [n] button appears on the sales screen showing how many sales are waiting; click it when you're ready. A success message confirms how many synced.
• Next to the button, Edit Offline Sales opens the queue so you can review, edit or delete a queued sale before it posts.

Either way, the offline token prevents duplicates — a sale can't post twice, even if a sync is interrupted partway and retried. Synced sales become ordinary sales attached to your location and register, inventory adjusts, and you can open one afterwards to fix a customer or a detail like any other sale (see returns, exchanges and edits for after-the-fact changes).

Reset the offline data

If a register's cached data ever gets into a bad state — stale items, a broken cache after a browser hiccup — go to Store Config → Application Settings and click Reset Offline Data. This clears the cached items, customers and settings in that browser; the cache rebuilds fresh the next time the sales screen loads while online.

Limits and gotchas

• Per device, per browser. The cache and the queue live in that browser's storage. Chrome and Firefox on the same till hold separate caches; a new till starts empty until primed.
• Don't clear browser data with sales queued. Clearing site data deletes both the cache and any unsynced sales. Sync first.
• Integrated hardware is out. Card terminals and PrintNode cloud printing need the network. Cash drawers on locally-connected receipt printers and browser printing may still work, but treat printed receipts as a bonus, not a given.
• Stock is not live. The offline screen sells from the cache without checking quantities; inventory adjusts when the sales sync.
• Big catalogs take time to cache. Items and customers download 100 at a time — give a large catalog its first uninterrupted sync well before you need it.

Common questions

The internet just went down and offline mode was never enabled — can I turn it on now? No. The cache is built while online; a register that never loaded the sales screen with offline mode on has nothing to fall back on. Enable it now for next time.

Do I have to set anything up on each register? Yes — once. Offline mode is enabled store-wide in Store Config, but every register device must load the sales screen while online so its own browser builds the cache.

Can I take card payments offline? Not through a terminal — integrated processing needs the network. You can record a Credit/Debit payment line offline as bookkeeping if you captured the card some other way, or take cash and checks and ask card customers to return.

Where are my offline sales before they sync? Queued in that browser, and listed under Edit Offline Sales on the sales screen, where you can edit or delete them before syncing. The Sync Offline Sales button shows the count waiting.

Could a sale be posted twice if the sync is interrupted? No. Every offline sale carries a unique offline token; the server skips any token it has already recorded, so retries are safe.

How fresh is the cached item and customer data? As fresh as the last sync cycle — the background worker refreshes the cache every Offline Mode Sync Cycle Time hours (default 24) while the browser is open and signed in.

Why does enabling offline mode also force HTTPS? The browser technology behind the cache (a service worker) only runs on secure connections. Cloud stores already run over HTTPS, so this is transparent.