Will Surcharge work with my one step type checkout?

Unfortunately there are a lot of extensions out there which replace the checkout. In our experience the ones we have come across tend to take away too much functionality, i.e. replacing Magento's default without adequately covering what Magento does. If your checkout extension ticks the following boxes chances are good that Surcharge will work out of the box:

1. Upon switching of the payment method the review section reloads 
2. Upon switching the credit card type the review section reloads (required if you want to surcharge based on credit card type) 
3. Custom Totals are displayed (if the extension also offers an Enterprise version this is a good sign) 
4. Custom Totals are displayed using their configured block 
5. Settings are honoured (tax inclusive vs tax exclusive settings for the totals are often ignored - see System > Configuration > Tax) 
6. Authorize.net Directpost is supported (without hacking it) 
7. Original layout handles for the checkout steps are honoured 
8. Totals sort order is honoured (System > Configuration > Sales)

The changes are made in the checkout extension, which is beyond the control of our code which is well-tested against the default Magento checkouts.

Rest assured that our extensions include a 30-day money back guarantee, so feel free to test out the extension on your own development site. If it doesn't work as intended, just let us know and we will refund your purchase.