The PayButton also makes it really easy to implement Refunds.

Your transaction is based on a set of MPTransactionParameters and provided to [MposUi createTransactionViewControllerWithTransactionParameters:].

To perform a full or partial refund, you need to create new MPTransactionParameters with the transactionIdentifier the of previous charge transaction. For partial refunds, you need to specify the amount that should be refunded.

Here's how you can perform refunds:

- (IBAction)refund:(id)sender {
    MPUMposUi *ui = [MPUMposUi initializeWithProviderMode:/*...*/];

    ui.configuration.summaryFeatures =
    // Add this line, if you want to offer printed refund receipts
    // MPUMposUiConfigurationSummaryFeaturePrintReceipt |

    MPTransactionParameters *parameters =
    [MPTransactionParameters refundForTransactionIdentifier:@"<transactionIdentifier>"
     ^(id<MPTransactionParametersRefundOptionals>  _Nonnull optionals)
         optionals.subject = @"Refund for Bouquet of Flowers";
         optionals.customIdentifier = @"yourReferenceForTheTransaction";

         // For partial refunds, specify the amount to be refunded
         // and the currency from the original transaction
         // [optionals setAmount:[NSDecimalNumber decimalNumberWithString:@"1.00"] currency:MPCurrencyEUR];

    UIViewController *viewController =
    [ui createTransactionViewControllerWithTransactionParameters:parameters
                                                       completed:^(UIViewController *ui,
                                                                   MPUTransactionResult result,
                                                                   MPTransaction* transaction)
        [self dismissViewControllerAnimated:YES completion:NULL];

        UIAlertView* alert = [[UIAlertView alloc] initWithTitle:@"Result"

        if (result == MPUTransactionResultApproved) {
            alert.title = @"Refund was made!";
        } else {
            alert.title = @"Refund was declined/aborted!";

        [alert show];


    UINavigationController *modalNav = [[UINavigationController alloc] initWithRootViewController:viewController];
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) {
        modalNav.modalPresentationStyle = UIModalPresentationFullScreen;
    } else { // Show as Form on iPad
        modalNav.modalPresentationStyle = UIModalPresentationFormSheet;
    [self presentViewController:modalNav animated:YES completion:NULL];

As a result, you will receive one of the following:

  • The original transaction that now contains information about the refund in the transaction.refundDetails;
  • An error indicating why refunding the charge failed.

To check if a transaction can be refunded in general, have a look at transaction.refundDetails.status.