The answer would appear to be -- it depends whether your divorce is taking place in California or England and Wales. Here is a truly amazing article from the English Telegraph. This is an extract from the article:
"Madonna and Sir Paul McCartney appear to have been charged hundreds of thousands of pounds more than the hourly rate would have demanded, documents show, a practice known as “marking up. The Conservative peer, who represented the Prince of Wales and the Duke of York in their divorces and remains solicitor to Princes William and Harry, appears to have charged her clients more than twice as much as the rate for the actual number of hours she had recorded as having spent on their cases, according to internal time sheets. The sheets, seen by The Daily Telegraph appear to show that a six-figure sum was added to bills of both Madonna and Sir Paul, as well as at least seven other clients in a column headed ''mark up. In one case a £14,000 bill for work on the former Beatle’s divorce from Heather Mills shows a “mark up” to £150,000." Read the full article.
Just to let you know I am an English Solicitor admitted to and practicing in California and I have NEVER included such a mark up on any of my bills.