IMEI number is very important for all mobile and smart phones. because for each mobile or smart phones there is one and unique IMEI number. so that, you could not find two mobile devices with same IMEI number.
However by using imei number in billing software in mobile stores, we can trace and a perfect report of invoices without any mistakes. so if an imei number entered twice in purchase vouchers, it will shows us that a mistake has been happen.
in iGreen software also we have a perfect focus on using IMEI number to record purchases and invoices to get accurate reports of sales profit.