Question:
Some suppliers surprise me with author's alteration charges on my invoice. What should I do?

Answer:
Fortunately, this practice isn't as common as it was several years ago. You shouldn't suffer in silence if you're being surprised by extra charges about which you were unaware until the invoice arrived. Make it clear that:

• 
  you want to be informed in writing as soon as the extra charges are identified.
• 
  every extra charge should be accompanied by an explanation of steps that can be taken to avoid the charge on subsequent jobs.

If these instructions aren't followed, put your wishes in writing. You may opt for putting the instructions on your purchase order. And if you fail to eliminate "surprise charges" after this, you can probably conclude that you are dealing with a supplier that has internal communication difficulties and/or inflexible systems that are not customer-friendly.