why whatsapp can't send video file more than 9 MB?

hi all gurus,

I have Huawei Honor 4C and Huawei G610, i can receive video files through Whatsapp upto 16MB but can't send file size more than 9 MB :( ....
can somebody help me to overcome this problem as Whatsapp limit is 16MB.

please guide me.

regards.