Excel "Does Not Equal" (<>)
In Excel, "does not equal" is written <>.
In a comparison
=A2<>"Paid"
This returns TRUE or FALSE.
In IF
=IF(B2<>"Paid","Follow up","")
In COUNTIF and SUMIF
Inside criteria, the operator goes in the quotes:
=COUNTIF(B2:B7,"<>Paid") =SUMIF(B2:B7,"<>Paid",C2:C7)
"<>" on its own means "not blank".