Do you bill for invoicing time?

When you’re setting your consulting fees, do you consider invoicing to be billable or non-billable time? Depending on how you set up your fees and contracts, you might designate time spent invoicing as administrative work — the cost of doing business. Or you might consider invoicing part of client and project management — and bill for it.

I’m curious about how my readers handle invoicing. Really, all paths may lead to the same place. If you put invoicing under administrative time, it will be absorbed into your fees. If you put it under project management, your project fees will be higher. What do you do?