lookup/countif

[LSRI24]

Hi, I dont know how and have been trying to add a calculated field to show if a phone number is present in another table in order to apply a group to it. 

the excel formula can be one of these two: =if(vlookup(A1,'sheet2'A:B,2)=0,"present","not present")

or =if(countif(A1,'sheet2'B1:B30)=0,"not present","present")

i dont mind either method, i just need to assign a grouping to the phone number depending if it is present on a separate list - shown as sheet 2 in the example

Thanks in advance for your help!