Dynamic Currency Conversion (DCC) for Payment Pages


Process overview

Typical DCC payments consist of two requests:

  • CURRENCYRATE request – This is used to retrieve an up-to-date conversion rate from a DCC provider. This is processed while the customer is on the Payment Pages, prior to confirming the purchase. We use this information to calculate the amount in the customer’s local currency and display this as an option for payment.

The customer will be offered a choice to pay in either the currency you specify in the POST, or the local currency associated with their card. (If these two currencies are the same, the payment will be processed immediately in this currency).

  • An AUTH request – Once the customer has decided on the currency for the payment, an AUTH request is processed. This is to request the customer’s bank to authorise the payment in the customer’s preferred currency.


What the customer sees



Payment choice


The customer is initially shown the payment choice page, where they can select the payment type that they wish to use. This differs from the normal choice page in that the amount is initially hidden. This is because the currencies and respective amounts to be offered to the customer have yet to be established. This comes after the customer enters their payment details on the next page.

Payment details


If the customer chooses a payment type that supports DCC, they are informed that they are able to pay in an alternative currency to the currency submitted in the POST. Here they will be able to see the amount in the currency you submitted in the request.

We will use the card number (PAN) entered by the customer to establish their local currency, by submitting the information in a CURRENCYRATE request. The conversion rate partner will supply a conversion rate that is used to convert the amount in the currency you submitted in the request to an amount in the customer’s local currency.

If the cardholder’s local currency is the same as the submitted currency, the customer will not be shown a conversion rate and instead will process the payment in this currency (skipping the currency choice page described below).

  The amounts paid in the customer’s currency have a small fee added to them to cover the cost of the conversion by the third-party conversion rate provider. This fee is determined by calculating a percentage of the amount in the customer’s currency and adding this to the total amount. For further information, please contact your conversion rate provider.

  If the payment type selected does not support DCC, the payment flow is not affected and the customer will complete the payment in the currency specified in the POST.

Currency choice


The amounts in both currencies are displayed on the currency choice page. The customer will be able to choose between paying in either currency.

  If the customer changes their card number (PAN) at this stage, before clicking “Pay Securely“, we will re-establish the customer’s local currency using the new card and perform another CURRENCYRATE request to retrieve the new conversion rate. The customer will be redisplayed the payment details page, along with the following warning that the new amounts calculated may differ from the amounts previously shown:


Once the payment currency has been selected, a subsequent AUTH request will be processed by your acquiring bank. This uses the currency and respective amount chosen by the customer on the Payment Pages.

Response page


Following a successful DCC payment, the customer is shown the response page with details of the transaction processed. This includes information on the currency conversion performed on the transaction.



To enable DCC on your account, please contact our Support Team. There are two methods to enable DCC on your account:

  1. Support can configure your live site in such a way that all requests, where the customer’s payment type supports DCC, are processed as DCC. The request you submit to the Payment Pages remains unchanged from a standard authorisation.
  2. Including the field dcctype with the value “DCC” in your POST will result in DCC being performed on a request, if the customer’s payment type supports it. Not including this field in your POST will result in a normal authorisation request being processed, without the customer being able to choose an alternative currency.

  For DCC requests, it is imperative that you submit a currency that is supported by your account. This is to ensure the correct currencies are used when performing currency conversion.


DCC field specification

Following CURRENCYRATE requests, we will return additional DCC fields for your records, as listed in the table below. These fields are displayed for the CURRENCYRATE and AUTH requests in MyST.

The fields can be returned in a URL notification on completion of a transaction. Include the fields shown below in order to include DCC information. They can also be included in an email notification (contact our Support Team to enable this).

Field name Description
dccbaseamount The base amount the customer has paid in the submitted currency (£10.50 is 1050).
dcccurrencyiso3a The currency you submitted in the POST to Payment Pages.

Whether or not DCC is enabled on your account:

1 – Your Trust Payments account is enabled for DCC.

0 – Your Trust Payments account is not enabled for DCC.

dccconversionrate The conversion rate used to convert the amount in the submitted currency to the amount in the customer’s currency.
dccconversionratesource The source of the conversion rate provided by the DCC provider.
dccmainamount The main amount the customer has paid in the submitted currency (£10.50 is 10.50).
dccmarginratepercentage The percentage used to calculate the currency conversion fee, applied to the amount in the customer’s currency.

The following values can be returned:

  • 1 – DCC Offered & Accepted
    The customer has accepted the offer of DCC and has chosen to pay in their card issuer's currency.

  • 2 – DCC Not Available
    The customer pays in the merchant's currency. (e.g. the CURRENCYRATE request encountered an error)

  • 3 – DCC Offered & Refused
    The customer has refused the offer of DCC and chosen to pay in the merchant’s currency.
dccprovider The institution that provides the conversion rate.
Was this article helpful?
1 out of 1 found this helpful
Have more questions? Submit a request