=sumproduct(--(a1:a5000="C"),--(b1:b5000)="NP")
will give the count of all customers and not paid combination

"Irv" wrote in message
...
How do I write a formula that counts the number of cells in columns "A" &
"B"
that has the letter "C" (in row "A") and "NC" (in row "B")?

For example: Column "A" has a series of C's (Customers) and V's (Vendors)
and column "B" has P (Paid) or NP (Not Paid).