Play arts Kari spike spiegal question
 

I know that playarts Kai figures have serial numbers. I have 2 play arts kai cowboy bebop spike figures boxed and cannot find a stamped serial number on either of them. Does anyone else have playarts kai cowboy bebop spike with no visible serial number or is it somewhere else besides bottom of the box? I've been watching videos and no one seems to have a serial number. Please help