GSTR2 in Tally

Hello experts
I record the purchase bill number without pretext in my books TALLY.Ie Actual purchase bill no is GST/17-18/123. I take this bill no in my book as 123. During filing gstr2 i accept this bill no. without any correction in GST portal.

Is it correct or not.

Mostly i omit this pretext while recording purchase. Most of the supplier issue the tax invoice with pretext.(I also do the same)

Let i know is there any problem will arise in the final submission of GSTR3.

Thanks and regards