The config key route allows you set a regular expression for card patterns that are allowed so if all the cards are 246068XXXX that they can't use and that pattern doesn't match any existing ones it would be worth using. You'll find more information on how to do this here. <a target="_blank" href="https://www.papercut.com/kb/Main/RegularExpressionsForCardNumbers" rel="noreferrer noopener">https://www.papercut.com/kb/Main/RegularExpressionsForCardNumbers</a>