Unused toll fees are only refunded if the user closes the account or takes advantage of a money-back guarantee.

Florida's Turnpike Enterprise converted the Homestead Extension of Florida's Turnpike, the Sawgrass Expressway, and the Veterans Expressway to open road tolling, utilizing the SunPass transponders, in September 2010, February 2011, April 2014, and June 2014 respectively, ceasing cash collection.

[10] SunPass is fully interoperable with E-Pass (from the Central Florida Expressway Authority), O-Pass (from Osceola County, which has been folded into E-Pass), LeeWay (from Lee County toll bridges) and the Miami-Dade Expressway Authority (MDX) toll roads.

[12] As a step towards this, the older battery-powered SunPass transponders were phased out by the end of 2015; new batteryless models can work with tolling equipment in other states.

[13][14] On July 29, 2013, Florida's Turnpike Enterprise made an interoperability agreement with North Carolina Turnpike Authority and its NC Quick Pass, allowing SunPass holders to utilize North Carolina's toll roads and lanes.

[17][18] The C-Pass system operated by Miami-Dade County Public Works on the Rickenbacker and Venetian Causeways was replaced by SunPass and pay-by-plate on September 23, 2014.

On May 28, 2021, the Florida's Turnpike Enterprise announced that its SunPass facilities would begin accepting E-ZPass.