When the internet drops, can you still take a card?
Picture a retail shop that loses internet for three hours on a Saturday afternoon. The cable line is cut two blocks away. The owner has a modern point of sale system that advertises offline mode, so the register continues to accept cards. Transactions are stored locally and will upload when the connection returns. The owner processes forty transactions during the outage. When the internet comes back, thirty-eight of them go through. Two are declined because the cards were over their limit. The owner has already handed over the merchandise. There is no way to get it back. The payment processor does not cover the loss. This is the risk you take when you run cards offline.
Most point of sale systems can operate without an internet connection for a limited time, but offline mode is not the same as online processing. When you process a card online, the terminal contacts the payment processor in real time, checks whether the card is valid and has available credit, and either approves or declines the transaction immediately. When you process a card offline, the terminal stores the transaction locally and attempts to process it later. The card is not checked at the time of sale. If the card is stolen, canceled, or over its limit, you will not know until the batch uploads and the transaction is declined. By then the customer is gone.
What offline mode actually allows
Offline mode is designed for brief interruptions, not extended outages. Most processors allow offline transactions for a few hours, and some systems will stop accepting cards after a certain number of offline transactions or a certain dollar amount. The limits vary by processor and by the type of terminal. Some systems require you to enable offline mode manually. Others switch automatically when the connection is lost.
When the connection returns, the terminal uploads the stored transactions in a batch. The processor attempts to charge each card. Approved transactions are funded normally. Declined transactions are not funded, and you are responsible for collecting payment or absorbing the loss. The processor does not guarantee offline transactions. If the card is declined, you have no recourse except to contact the customer and ask them to pay another way. Most customers will not respond.
Offline mode also does not work for every transaction type. Refunds, voids, and gift card lookups require a live connection. EMV chip cards can be processed offline, but the chip generates a cryptogram that is only valid for a limited time. If the batch does not upload within that window, the transaction may be declined even if the card is good. Contactless payments and mobile wallets generally do not work offline at all.
When a backup line is cheaper than the risk
A cellular backup line costs between thirty and seventy dollars per month depending on the carrier and the amount of data. A point of sale system uses very little data. Most transactions are a few kilobytes. Even a busy shop will use less than a gigabyte per month. The backup line does not need to be fast. It only needs to be available when the primary line is not.
The cost of turning away customers depends on your volume and your margins, but for most retail and service businesses, a single busy afternoon without card processing will cost more than a year of backup internet. If you process fifty transactions in an afternoon and your average sale is forty dollars, that is two thousand dollars in revenue. If you lose half of that because customers leave when you tell them the card reader is down, you have lost a thousand dollars. A backup line for a year costs four hundred to eight hundred dollars.
The other cost is the offline risk. If you process cards offline and two percent of them decline when the batch uploads, you lose that revenue and you have already delivered the product or service. Two percent of two thousand dollars is forty dollars per outage. If you have four outages per year, that is another hundred and sixty dollars in unrecoverable charges, plus the time spent trying to collect.
Test it before you need it
Most shops do not know whether their point of sale system has offline mode, whether it is enabled, or how to activate it. The time to find out is not during an outage. Unplug the modem and try to process a test transaction. If the terminal allows it, let it sit offline for an hour and then reconnect and see whether the transaction uploads. If the terminal does not allow it, call your processor and ask whether offline mode is available and what the limits are.
If you have a backup line, test the failover the same way. Unplug the primary connection and make sure the router switches to the cellular link. Process a transaction over the backup and confirm that it goes through. Time how long the failover takes. If it takes more than a minute, you may need to reboot the terminal or the register to get it to reconnect.
This is part of what a managed network service includes. RedCyfer configures and tests failover before an outage, monitors both links, and confirms that point of sale systems reconnect when the primary line returns. For shops where card processing is the primary revenue source, a backup line and a tested failover plan are not optional.