Your machine's bill validator can be set so that certain denominations are not accepted and returned to the user.
First, remove the bill validator from the machine's vault. You'll need a small Hex screw to do so, and a picture walkthrough can be found in our mounting instructions.
Once removed, unscrew the four locations in red with a small Philips-head screwdriver to remove the metal retaining bracket.
The DIP switches are circled here:
Using a toothpick flip the switches to ON in order to DISABLE certain denomination bills, according to the Software Information Sheet for your currency.
The Software Information Sheet can be found on JCM's software search page. To find yours, fill in your country, then hardware (likely iVIZION 100), stacker type (SU), and protocol ID (003). If you have questions on your particular bill validator or firmware. Please contact us at email@example.com.