How does a POS take card payments offline?
It saves the payment and sends it later. The payments world calls it store and forward. The card still gets read the normal way, but instead of asking the bank for an approval on the spot, the device keeps the payment in a secure queue and uploads it when the connection comes back.
- Customer taps or dipsOn a reader or terminal that supports offline mode
- Payment is savedStored on the device, marked pending
- You reconnectThe queue uploads on its own
- Bank says yes or noApproved payments deposit, declines show up in your history
The gap between step two and step four is the whole story. While you're offline, nobody has checked whether that card is good. Most cards go through fine once they upload. Some don't, and by then the customer has left with the goods. That's why every offline mode comes with a time limit and why most let you cap how much a single offline sale can be.
What works offline on a cloud POS, and what doesn't?
Ringing up sales and taking cash keep going on almost any modern POS. Cards depend on the hardware and the payment type. This is the usual pattern, though every system draws the lines a little differently.
- Usually works
- Works with limits
- Usually needs a connection
| Task | Offline? | The catch |
|---|---|---|
| Ringing up items | Yes: Yes | Uses the item list already saved on the device |
| Cash sales | Yes: Yes | Sync to your reports when you reconnect |
| Chip and contactless cards | Limited: On supported hardware | Offline mode has to be on, and the approval comes later |
| Tap to Pay on a phone | No: Usually not | Phone-based tap usually needs a live connection |
| Keyed-in card numbers | No: Usually not | Higher fraud risk, so processors tend to block it |
| Gift cards and pay later | No: Usually not | The balance or approval lives on someone else's server |
| Online orders | No: Paused | New web orders show up once you're back online |
| Loyalty and reports | Limited: Catch up later | Points and totals may need a fix after the upload |
If you sell from a truck window or a market tent, our mobile POS page covers the phone and reader side of this. If you're still deciding between a cloud system and an old-style server, start with cloud POS explained.
How does Square's offline mode work?
Square calls it offline payments, and it's the offline POS we set most people up on. Here's what Square's own help pages say about which devices it covers, how long it lasts and the rules that come with it.
On Square Free
Which Square devices take cards offline?
- Square Register, Square Terminal and Square Handheld.
- Square Stand, first and second generation.
- Square Reader for contactless and chip, second generation, plus the first generation version 3.
- The magstripe reader, only when a supported reader or Stand is connected too.
Not offline: Tap to Pay on iPhone and Android, manually keyed cards, Cash App Pay, Afterpay, Square Gift Cards, EBT, the Invoices app, services mode in Square Point of Sale and Kiosk Lite. Online orders may not show up until you reconnect.
How long can Square stay offline?
- The moment it drops
An offline session starts on its own
If offline payments are allowed, the device retries a failed payment once and then switches to offline mode by itself. A banner with a countdown shows how long you have left to reconnect.
- Up to 24 hours
Readers and Stand can keep taking cards
On Square Reader and Square Stand, an offline session lasts 24 hours. After that you have to reconnect before you can take offline payments again.
- Within 24 hours
Upload, to be safe
Square highly recommends uploading within 24 hours on every device, Register, Terminal and Handheld included, to cut the risk of declines and chargebacks.
- 72 hours
Pending payments expire
Anything still not uploaded 72 hours after the session started expires, and Square can't recover or reprocess it.
What should you know before relying on it?
Declines are on you
You won't get a decline notice while you're offline. Declined, expired and disputed offline payments are your responsibility, and Square can't contact the customer for you.
Don't sign out
With payments pending, don't sign out, delete the app, switch modes or locations, or factory reset the device. The pending payments are lost for good. Restarting is fine.
Set a per-sale limit
In your offline settings you can cap the amount of a single offline payment, and choose cards and cash or cash only, separately for an internet outage and a Square outage.
Refunds wait
An offline payment can't be refunded until it has uploaded. Loyalty points from offline sales have to be added by hand afterward.
Source: Square Support Center, "Process offline payments." Square turns offline payments on for sellers who haven't opted out, and the same processing fees apply as online.
What should you set up before the internet goes down?
Do it on a quiet afternoon, not in the middle of a rush with a line out the door. Ten minutes of setup covers most of it.
Check that offline mode is on
Some systems switch it on for you and some don't. Look in the checkout or payment settings, and decide whether you want cards and cash offline, or cash only.
Set a cap for a single offline sale
If your system lets you, pick a limit that matches your normal ticket. A decline on a coffee stings. A decline on a big order hurts.
Use hardware that supports it
Offline card payments usually need the provider's reader or terminal, not Tap to Pay on a phone. Check the provider's list before you buy.
Add a backup connection
A phone hotspot, a second internet line or a terminal with its own cellular data covers most outages. It's usually a better fix than relying on offline mode for hours.
Tell your staff the rules
Ask for chip or tap instead of a swipe, don't sign out of the app or reset a device with payments still pending, and know who to call.
Test it once
Turn off the Wi-Fi on a slow day, ring a small sale, then reconnect and watch it upload. You'll know exactly what the screen looks like when it happens for real.
Is a cloud POS with offline mode better than a fully offline POS?
For most small businesses, a cloud POS with a good offline mode is the better fit. A fully offline POS, meaning software installed on a computer in your store with the data saved locally, does have a real advantage: it doesn't care whether the internet is up. It just doesn't solve the card problem on its own.
| Cloud POS with offline mode | Fully offline POS on a local computer | |
|---|---|---|
| Ringing up with no internet | Yes, for a limited time | Yes, for as long as you like |
| Card approvals with no internet | Saved and approved later, on supported hardware | Still need a connection to the processor, unless the card terminal has its own offline mode |
| Reports and items from home | Any browser or phone | Only on that computer, or with remote access set up |
| Backups and updates | Handled by the provider | Your job. If the computer dies, so can your data |
| Online orders and more than one location | Built in on most systems | Hard or not possible |
| Cost to start | Often free software, plus hardware | Some programs are free to download, others charge for a license, plus a computer |
Go cloud with offline mode if
- Outages are short and now and then
- You want to check sales when you're not there
- You sell online or in more than one spot
- You'd rather not babysit backups
Look at local software if
- You're somewhere with no internet for days at a time
- You mostly take cash
- You're comfortable keeping your own backups
- Your card terminal handles its own offline payments
To be fair to local systems: a well-kept one is fast and doesn't flinch when the internet does. If you're searching for a free offline POS to download for a PC, check three things before you install it: who processes your cards, how you back up the data, and who you call when it breaks.
Who needs a POS that works offline?
Anyone who can't stop selling when the signal does. Some businesses run into it every week:
- Food trucksParking lots and festivals with one bar of signal
- Markets and pop-upsA tent in a field, a crowd of phones on one tower
- BarsBusy nights when the Wi-Fi gets crowded
- Shops on one lineA single internet connection and no backup
For everyone else, offline mode is insurance. You might go months without needing it, and you'll be glad it was on when you do. When you're comparing systems, our best free POS systems roundup notes which ones take cards offline.
Questions people ask
Can a POS system work without internet?
Many can, for a while. Most cloud POS systems have an offline mode that keeps ringing up sales and saves card payments on the device, then uploads them when you reconnect. A local POS that runs on its own computer keeps working indefinitely, but still needs a connection to approve cards.
Is it safe to take card payments offline?
It's safe for the card data, which stays encrypted on the device. The risk is yours: nobody checks the card until the payment uploads, so a declined card means a lost sale. Keep a limit on offline sale amounts, upload as soon as you can, and ask for chip or tap instead of a swipe.
Which payments don't work offline?
It depends on the system, but keyed-in cards, tap to pay on a phone, digital wallets that need an app connection, and gift card balances often don't. Online orders and invoices also wait for the connection. Check your provider's list before you count on it.
Is there a free offline POS for a PC?
There are free POS programs you can download and run on a Windows PC without internet. They're fine for cash and keeping track of sales. To take cards you'll still need a processor and, for most, a connection. A cloud POS with offline mode usually gets you further for the same price. Our cloud POS guide covers the tradeoffs.
How do I keep selling if the internet goes down?
Turn on offline mode before you need it, keep a phone hotspot ready as a backup connection, and know what still works on your setup. Cash always works. Our mobile POS page covers hotspots and readers for selling on the go.
If you go with Square
How long can Square work offline?
On Square Reader and Square Stand an offline session lasts 24 hours, then you have to reconnect. On every device, payments that haven't uploaded 72 hours after the session started expire and can't be recovered. Square recommends uploading within 24 hours everywhere.
Does Square charge more for offline payments?
No. Offline payments carry the same processing fees as any other in-person card payment. Current rates are on our pricing page.