Missing purchase invoces

MURALIDOSS (INCOME TAX PRACTITIONER)   (1314 Points)

28 July 2018  

A  GST HOLDER PURCHASED FROM 3 SUPPLIER, HE ENTERED ONLY 2 SUPPLIER"S  PURCHASE ITC IN GSTR 3B FROM jULY 17 TO DECEMBER-17, NOW ONLY WHEN WE CHECK 2A ONLYWE CAME TO KNOW THAT ACCOUNTANT NOT ENTERED  IN GSTR 3B .

CAN I ADD ALL THOSE MONTHS MISSING PURCHASE ITC'S IN JULY GSTR 3B?

AND

HE FORGOT GSTR1 ALSO FROM JULY17 TO DEC-17 SALES, CAN MAKE OUTPUT IN JULY 18 GSTR 1?

ADVISE..