Are there any POS systems that keep taking orders offline and sync everything once connectivity returns?

Yes — many modern POS systems support offline mode or offline-first operation, where they can keep taking orders during an internet outage and then sync data back to the cloud once connectivity returns.

Common examples

A few well-known POS platforms with offline capabilities include:

• Square POS — can continue accepting card payments offline for a limited time and sync later
• Clover — supports offline payments/orders in some setups
• Toast — built for restaurants and supports offline operation in certain workflows
• Lightspeed — offers offline selling modes depending on the product
• Shopify POS — can keep selling and sync when back online
• Revel Systems — enterprise POS with offline support
• Oracle MICROS / NCR — often used in larger retail/restaurant environments with offline resilience

Important caveat

“Offline” can mean different things:

1. Order-taking offline only: the POS stores tickets locally and syncs later.
2. Payment processing offline: cards may be accepted offline, but this is riskier and often limited.
3. Full local-first operation: the system keeps running almost entirely from local devices and syncs the cloud later.

Some systems only work offline for a short time, or only for certain functions. Also, offline card payments may be subject to fraud/liability risk and regulatory constraints.

What to ask vendors

If you’re evaluating POS systems, ask:

• Can it take orders fully offline?
• Does it sync orders, inventory, and customer data automatically when back online?
• How long can it operate offline?
• Does offline mode work on all devices or only some?
• Are payments supported offline, or only order entry?
• What happens if multiple terminals are offline at once?

If you want, I can also give you a shortlist by industry (restaurant, retail, food truck, etc.) or a comparison table of the best offline-capable POS systems.