Can interest be charged only to certain customers?

I was wondering if there is a way to charge only certain customers interest?

We have some customers we wish to charge interest to, while other customers we don't.

We have multiple people working in Sage at any given time, so it is a huge pain to jump into and out of single user to print off/email statements with interest, then turn off the interest, then print/email the other statements...then switch back to multi user...

I really wish there was a check box under Options within each customer that you could select whether you want to charge this customer interest or not.  Just like there is a check box to select if you want to Produce Statements for this Customer.  I feel this could be a very helpful feature.