POS offline mode: what each system does when the internet drops

POS offline mode keeps a card terminal taking payments when the connection dies, and every major system has some version of it. The settings differ sharply, though, and the risk does not move: Square's and Toast's documentation say outright that a declined or expired offline payment falls on the merchant, not the processor. Clover's and Shopify POS's documentation do not use those words, but in our reading what they describe (a staff prompt per transaction, or contacting the customer to collect) leaves the same exposure with the merchant. Only Shopify POS makes you switch card acceptance on yourself.

That makes this a settings problem, not a shopping problem. If you already run one of these systems, the useful question is not whether it works offline but what limit it is carrying right now, how long it will keep storing cards, and which tenders go dark the moment the line drops. Below is what each vendor's own documentation said when we read it on October 25, 2026.

What POS offline mode actually does, and the one thing it cannot do

An offline payment is stored, not authorized. The terminal reads the card, writes the transaction to its own storage, prints or emails a receipt, and sends nothing to the card network until it has a connection again. Shopify's help page is blunt about the consequence: offline transactions are not routed to the payment processor, so a failure may not surface until you reconnect.

Nothing in that flow checks whether the card has money on it, whether it has been reported stolen, or whether the issuer will honor it days later. That is the trade: you keep selling, and you accept a batch of payments whose outcome you learn about afterwards. Toast states the ceiling plainly in its offline mode setup guide, updated October 14, 2026 - "If a payment declines once you're back online, it can't be re-run."

In our view that is why the per-transaction limit matters more than the feature. Offline mode converts an outage into a small, bounded credit risk, and the limit is the only thing deciding how small.

Square turns offline payments on unless you opted out

Square's US help page for offline mode sets two clocks. For Square Register, Terminal and Handheld you must upload offline payments within 72 hours of the start of the offline session, with 24 hours recommended; for the older Square Readers and Square Stand, the page says you have 24 hours to accept offline payments.

The page also documents a default change with a date on it. Starting in March 2026 Square emails sellers to review their offline settings, and in April 2026 "offline payments will be automatically enabled on all your devices" for sellers who take no action. The page states the position directly: offline payments are automatically allowed on all your devices unless you opt out.

The per-transaction cap is yours to set, anywhere from $1 to $50,000. We found no total or daily cap on the page we read - only the per-payment maximum - so a $50,000 setting on a busy counter is not bounded by anything else Square documents there. Liability is not hedged either: "You're responsible for any expired, declined, or disputed payments accepted while taking offline payments," and Square says it cannot contact your customers about them on your behalf.

If you sell food or run a market stall, the practical setting is a cap near your largest honest ticket, not near your plan's maximum. Square is one of 124 products in our payments and banking category as of October 2026.

Toast goes offline after 40 seconds, and keeps taking cards

Toast's offline payments overview gives the trigger a number: "40 seconds after no Internet connectivity or during a Toast outage, your Toast POS device enters offline mode." Cash and card payments still process; gift cards, loyalty redemptions, Tender API payments, text to pay, customer credits, comp cards and house accounts do not.

The card behavior is a two-way setting, and in our view the recommended option is the riskier one. Toast's setup guide offers "Continue accepting card payments without waiting for authorization (recommended)" or "Do not accept card payments (wait until authorization is available)," and says background card processing is on by default. In Australia, Canada, Ireland and the UK it is enabled by default and you must contact Toast Customer Care to change it.

Two details from that guide are worth writing on a sticky note by the terminal. You can only change the setting while the POS is online, so a restaurant that decides mid-outage to stop taking cards cannot. And authorizations may expire as early as 24 hours after the transaction, which Toast says can result in a loss to the business.

Toast does support a transaction limit, above which a manager must override each individual sale in offline mode. For a full-service restaurant, in our view that override is the control worth setting before a storm, because it puts a human in front of the one $400 check that would hurt.

Clover will store cards for a week by default

Clover's developer documentation on handling offline payments, updated March 24, 2026, puts the default window far out: Clover Mini and Flex are set to take offline payments for up to 7 days. Merchants can set limits on the transaction amount for offline payments and on the total amount processed in an offline state.

Clover's model differs from the others in one respect we like: the card is not silently stored. When an offline payment is attempted, the merchant is prompted to accept or decline the payment with an offline challenge, so a staff member makes the call transaction by transaction. The same page tells developers building on Clover that by using any of the offline payments settings, "you assume responsibility for warning the merchant of any possible risk."

In our view, seven days is a long time to carry unauthorized sales. If your Clover setup still has the default, we'd say the cheapest change you can make this week is to shorten it to something that matches how long your internet actually stays down.

Shopify POS is off until you turn it on

Shopify is the outlier, and in our view the safer default. Its offline payments help page requires you to activate offline payments in your Shopify admin before the POS will take cards without a connection, and staff need the specific "Accept offline credit and debit payments" POS permission. You also need POS app version 9.14.0 or later.

The page documents two limits rather than one: a device daily limit that caps the total of all offline card payments on a device per day, and a transaction limit that caps a single order. It does not state how long offline payments can be stored, and recommends reconnecting ideally within 24 hours to reduce the risk of declined payments. Declines show a "Card declined" badge on the order, and Shopify's suggested remedy is to contact the customer using the email or phone number collected at checkout - which is the argument for collecting one during an outage.

The exclusions are regional as well as technical. Swiped cards, Tap to Pay on iPhone, Tap to Pay on Android and manual card entry are not supported offline; Canadian businesses cannot accept Interac offline, Australian businesses cannot accept eftpos, and offline payments are not available for retail locations in France. Shopify sits in our e-commerce category alongside 146 other products as of October 2026.

Stripe Terminal makes offline mode your code's problem

If you are building your own point of sale rather than buying one, offline is not a toggle. Stripe's Terminal offline documentation describes storing payments locally on the POS device or smart reader, with the SDK or reader forwarding them automatically once a connection returns, and exposes offline events to your application through callbacks - which means your app decides what the cashier sees and what limits apply.

The payment-method table is where the surprises are. Swiping is not allowed offline at all; NYCE, PULSE, STAR, girocard, Interac and QR code payments are unsupported; and in the European Economic Area customers must insert the card and enter a PIN. Tap to Pay on Android does not support offline mode, and Tap to Pay on iPhone offline is in private preview and limited to Visa, Mastercard, Discover and American Express contactless cards.

That contactless restriction is the one that catches teams who sell with a phone instead of a terminal. Our walkthrough of Tap to Pay on iPhone for business covers the cards that setup already refuses; offline mode narrows the list further.

Which payment types stop working offline

In our reading of the vendors' lists, the pattern across all five systems is that anything requiring a lookup stops. Balances, loyalty points, government benefits and buy-now-pay-later all need a live call to someone else's server, and a stored transaction cannot make it.

• Square: Afterpay, Cash App Pay, Square Gift Cards, Tap to Pay on iPhone and Android, manually entered cards, and EBT/SNAP.
• Toast: gift cards, loyalty redemptions, Tender API payments, text to pay, customer credits, comp cards and house accounts.
• Shopify POS: swiped cards, Tap to Pay on iPhone and Android, manual card entry, Interac in Canada, eftpos in Australia.
• Stripe Terminal: swiping, NYCE, PULSE, STAR, girocard, Interac, QR code payments, and Tap to Pay on Android.

In our view cash is the tender least likely to fail, which is the unglamorous reason a float and a receipt book still belong under the counter. If your gift card program is a real share of revenue, an outage hits it fully and no setting changes that.

Who is liable if an offline card payment declines

Square's and Toast's documentation say it falls on the business, and in our reading Clover's and Shopify POS's documentation imply the same. Square: "You're responsible for any expired, declined, or disputed payments accepted while taking offline payments." Toast: "You are responsible for any declined, expired, or disputed payments taken in Offline Mode." Shopify directs you to chase the customer yourself. Clover's design asks a staff member to accept the risk per transaction.

We read these pages on October 25, 2026. Vendor terms and help documentation change without notice, and the operative document for your business is your merchant agreement, not a help article - so check the current pages and your own contract before you set a limit, and take professional advice where real money rests on it. This is general information, not legal advice.

Three settings to check before the next outage

1. Find your per-transaction limit and lower it to your largest routine ticket. Square lets you set $1 to $50,000, Shopify caps per order and per device per day, Toast requires a manager override above its limit, and Clover caps per transaction and in total.
2. Decide the window, not just the cap. Clover's 7-day default and Square's 72-hour upload deadline are very different exposures; pick the shortest one your business can live with.
3. Check the default you never chose. Square enables offline payments on all devices unless you opted out, Toast ships background card processing on, and Toast's setting can only be changed while the POS is online.

Then write the offline procedure down for staff: cap, which tenders to refuse, and that they must collect an email or phone number for every stored card payment. The systems above are among the 124 tools in our payments and banking category and the 67 in industry tools as of October 2026 - and if you build point-of-sale software, you can submit it to the directory for free.