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Network failover to cellular connectivity

Switch to cellular when the terminal can't access the internet through the network connection.

Network failover occurs when the payment terminal can't access the internet over the primary network connection (usually Wi-Fi or Ethernet), and switches to a cellular connection (3G or 4G). This enables you to continue making transactions when there is a problem with the internet access.

To make network failover possible, you need to either:

But as you can see in the scenarios below, there are situations when network failover isn't useful. The following alternatives are available:

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

Understanding network failover scenarios

There is a difference between network connectivity and internet connectivity. To process a transaction, the terminal must have internet access. The terminal uses its primary network connection (Wi-Fi or Ethernet) to reach the internet. There are two ways this can go wrong:

  • The terminal can't access the internet because it has lost the connection to your network.
  • The terminal is connected to your network but can't access the internet.

Let's look at how network failover works in these cases with cloud communications or local communications.

Scenario: No network connection - cloud integration


The terminal lost its primary network connection, and fails over to a cellular connection. The POS app sends the payment request to the Adyen payments platform, which forwards the request to the terminal. The terminal receives and processes the request over the cellular connection.

Scenario: No internet - cloud integration


The terminal is connected to the network through its primary network connection, but has no internet access. The terminal fails over to a cellular connection. If the POS app does have internet access, it sends the payment request to the Adyen payments platform, which forwards the request to the terminal. The terminal receives and processes the request over the cellular connection.

In this scenario, network failover to cellular connection on the Android payment terminals does not work.

If the POS app can't access the internet, network failover on the terminal doesn't solve the problem.

If the POS app has no internet access, it can't send and receive payment messages. Consider using a standalone terminal as a backup.

Scenario: No network connection - local integration


The terminal lost its primary network connection, and fails over to a cellular connection. The POS app is still connected to the network and sends the payment request to the terminal over the network. However, the terminal never receives the request because it is disconnected from the network.

In this scenario, network failover is not useful.

Consider alternatives:

  • Use a standalone terminal as a backup.
  • Enable offline payments.

Scenario: No internet - local integration


The terminal is connected to the network through its primary network connection. After receiving the request, the terminal tries to access the internet through the primary connection. After 36 seconds of not being able to connect to the internet, the terminal fails over to a cellular connection. The transaction is processed over the cellular connection.

In this scenario, network failover to cellular connection on the Android payment terminals does not work.

Using terminals with cellular connectivity

Most mobile and portable terminals have built-in 3G or 4G hardware and a pre-installed, activated SIM card. This allows the terminals to send and receive payment messages as packets over the internet through General Packet Radio Service (GPRS, which is an extension to cellular communication).

If these terminals can't reach the internet through their primary network connection, they automatically switch to processing payments using their cellular connection. They will also switch back to using the primary connection when this is available again.

Note that our terminals only support SIM cards supplied by Adyen. For exceptions see using a third-party SIM card.

Currently, we don't charge fees for using the cellular connection. In the near future this will change for Android terminals: we won't charge a fee for using the cellular connection to make payments or update the terminal, but you will need to buy data bundles to cover the expected data traffic of the apps that you have running on your Android terminals.

Mobile network operators around the world are ending coverage for 3G. This affects terminals that only support 3G for cellular connectivity.

Manage cellular connectivity on the terminal

By default, SIM cards are activated and cellular connectivity is enabled. Using our Management API, you can deactivate and activate the SIM card in individual terminals one at a time. If you deactivate a SIM card, the terminal can't use cellular connectivity. If you later enable the SIM card again, you also need to re-enable cellular connectivity on the terminal.

To deactivate or activate the SIM card in a terminal:

  1. Optional. To see the current activation status of a SIM card, make a GET /terminals/{terminalId}/terminalSettings request and check the simcardStatus.

  2. Make a PATCH /terminals/{terminalId}/terminalSettings request.

    In the request body, specify a connectivity object with the following properties:

    Parameter Data type Description
    simcardStatus String The status of the SIM card in the terminal that is specified in the path. Possible values:
    • ACTIVATED: the SIM card is activated.
    • INVENTORY: the SIM card is deactivated. The terminal can't use cellular connectivity.

    The response returns all terminal settings at the level where you made the request.

  3. If you activated a SIM card that was previously deactivated, re-enable cellular connectivity on the terminal:

    • On Android and non-Android terminal models that use the new menu structure:

      1. Select Settings > Network and enter your Admin & Settings passcode.
      2. Select Cellular and select the toggle to enable the SIM card.

    • On non-Android terminal models that use the old menu structure:

      1. Go to the Admin menu and enter your Admin & Settings passcode.
      2. Select Network > Cellular.
      3. Select the Cellular toggle to enable the feature.

    The terminal automatically selects the strongest available network that is supported by the terminal model. You can also select a network manually from the Device info menu.

Using a third-party SIM card

You can use a third-party SIM card on AMS1, S1U2, S1F2L, and S1E2L payment terminals in addition to the pre-installed SIM card provided by Adyen.

To enable using a third-party SIM, provide your account manager with the following details:

  • The Access Point Name (APN) that you received from your network operator.
  • The serial number of the terminal on which you installed the third-party SIM card.

The account manager will enable using the third-party SIM card for your terminal on the merchant level. To activate it, do the following:

  • Make sure that software version V1.93 or later is installed on your terminal.
  • Place the third-party SIM card in the second SIM slot of your terminal.

    Don't remove the pre-installed SIM card from its slot.

Your terminal will automatically prioritize the activated third-party SIM card. When you remove the third-party SIM card, your terminal will automatically use the pre-installed SIM card again.

Switch to a local network operator in Brazil

Regulatory requirements in Brazil allow roaming for cellular network traffic for up to 90 days. This is why Adyen supports switching to a local network operator in Brazil without the need to sign any additional contracts or install additional SIM cards.
On Android payment terminals, like S1F2, you can manually select a Brazilian network provider from the list of supported ones in the payment terminal menu. The payment terminals must be on software version 1.96 or later.

To switch to a local network provider:

  1. Go to Settings > Network and enter your Admin & Settings passcode.
  2. Select Cellular > Select operator.
  3. In the pop-up, select OK. This means the terminal will restart after you select a different operator.
  4. Select MULTI IMSI > Status > Enable.
  5. Select MULTI IMSI > IMSI. From the list of network operators, select:
    1. ARQIA to connect to TIM.
    2. ROAMING 1 to connect to Vivo.
    3. ROAMING 2 to connect to Claro.

When done, the payment terminal automatically restarts and applies the new settings.

After you manually switch to a different network provider, the terminal stays connected to that network even if the connection is weak. To change the network provider, you need to select a different one manually.

Using a cellular router

If your terminals don't have built-in cellular hardware, you can install a router with 3G/4G network failover. When the terminal can't reach the internet through its primary network connection, the terminal switches to an internet connection over GPRS. The terminal also switches back to the primary connection when this is available again.

To ensure you get the best cellular reception, you should also install external 3G/4G antennas.

See also