With established clients, I have always advanced fees that were short up to about $25 more or less for recordings. This is due to incorrect recording fees, intangible tax, quirks in a certain county.  (Recently, here in Ga there were recording fee changes).  I first call the company and if I agree to front my money; they have to send me a revised order first or I get the person's info who approved the extra fee.  When I fax or email back the info, I am sure I have the person's name who approved the additional fee if I don't have a revised order, along with an explanation of the reason their check was short and the correct fees for future reference.  I base it on my relationship with a particular client and their pay history, whether or not to pay additional recording fees up front for them.  I haven't had a problem.

On the other hand, there are other companies recently, who have shorted me on copies (particularly certified copy costs that I front, even though I always send a receipt).  I am dealing with those and will refuse any more requests from them unless they make it right!