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Best practices

Best practices for building a point of sale integration.

Preventing network issues

When you make a point of sale transaction, your cash register, terminal, and Adyen will need to be able to communicate with one another.

For networking requirements, and our recommendations on how to configure your network, see our network configuration documentation.

Handling network issues

When a transaction is declined because of a network connection issue, the error condition you receive for the transaction is UnreachableHost.

There are several ways you can continue making transactions when your primary internet connection is unavailable. These are:

Using 3G/4G failover

To use a cellular connection as a backup, you can either:

Using 3G/4G terminals

The Verifone V400m and e285 terminals have built-in 3G/4G hardware and pre-installed SIM cards. If your primary internet connection drops, these terminals will automatically switch to processing payments using the 3G/4G connection. They will also switch back to using your primary internet connection once this is available again.

To enable a 3G/4G terminal connection, contact our POS Support Team. There is an additional monthly cost for using this service.

Using a 3G/4G router

If your terminals don't have built-in cellular hardware, we recommend installing a router with 3G/4G network failover. To ensure you get the best cellular reception, you should also install external 3G/4G antennas.

Offline transactions

If your integration uses local communications, you can continue making in-store payments when there's a temporary loss of internet connectivity. There are two types of offline transaction:

  • Offline EMV: The payment terminal approves the transaction if the PIN that the shopper enters, matches the PIN on the EMV chip embedded in the card.
  • Store-and-forward: The terminal approves the transaction without any verification.

When your integration is online again, approved transactions are automatically forwarded to card issuers for processing.

You are fully liable for the risk of failed captures, chargebacks, and disputes related to payments that you process offline.

To make offline transactions, you will need to set a transaction floor limit. For more information, refer to the Offline transactions documentation

Generating compliant receipts

Card schemes have very specific requirements on what should be included on a receipt. These requirements differ per scheme and country, and can change. Receipts generated by Adyen have been certified as compliant by the card schemes that we support.

We strongly recommend generating receipts using the Adyen-generated receipt data, without alterations.

Card schemes will occasionally visit stores to verify that receipts being generated are fully-compliant. Non-compliant receipts can result in payments being charged back.

If you override this receipt data, or validate values against a hard-coded list, it is your responsibility to ensure that scheme requirements are met at all times.

For more information, see our point of sale receipts documentation.

See also