Hey, Typophiles! Turning to you for advice: I bill by the project, and have just finished laying out a report that I billed at 2.25 days. Only problem is that (for once!) I overestimated how long it would take – I really worked about 1.5 "days" on the project, including admin.
My question: do I follow-up once the project closes and adjust my fee downward, making clear the reason? Or do I take the money and run, since we all agreed on the scope and the rate in advance?