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Singapore regulations & registration

In-Vehicle Unit (IU)

The In-Vehicle Unit (IU) is the LTA-mandated ERP transponder mounted on the windscreen of every Singapore-registered vehicle; metallic window films can interfere with its operation.

The IU is a small RFID/microwave transponder bonded to the inside of the windscreen, used by Electronic Road Pricing (ERP) gantries to deduct toll charges. ERP-2 readers also use the IU for satellite-based congestion pricing on the second-generation system.

Metallic and metallised window films attenuate the radio signal between gantry and IU, potentially causing missed deductions and notification of violation. Ceramic, nano-ceramic and multi-layer optical films are signal-friendly and do not affect IU function.

For Singapore drivers this is one of the key reasons to choose a non-metallic film: premium ceramics like Platinum99 pass IU compatibility without issue.