Wrapping Authorize.net in an iFrame

I have always stayed away from using Authorize.net's SIM because it takes the user away from my site. However, one of my vendors gets around this by accessing Authorize.net in an iFrame. That way the rest of my Joomla template is still there, but entry of the credit card info is still on Authorize.net's site.

How could I modify the call to Authorize.net's payment processing so that it is done in an iFrame instead of reloading the page directly?

You would have to implement the DPM API of authorize.net in the authorize.net plugin:
developer.authorize.net/api/dpm/

Trust me, that is the right way to do it, but I don't think I have the PHP skills to do get it done.

Having the Authorize.net plugin handle DPM would solve a lot of PCI issues for a lot of people while keeping the checkout flow entirely on their own website. But apparently there are no plans for Hikashop to implement it.

Which is why I was hoping that there was some simple line to change in the SIM code to keep the call in an iFrame.

If it was just a few lines to change in the plugin, we would have already done it
Unfortunately, it's more complicated that that and will require proper development.

If you want us to do that properly for you (and we never said we didn't want to do it, just that it was not yet in the plans), you can request a quote via our contact form.