I am a partner who is looking to move to another firm. Can you provide some basic guidance as to how I should estimate my portable business?
Answer:
First, give yourself credit for what you have accomplished. Based on the negative stereotypes that lawyers share, one might expect that partner candidates are more prone to exaggerate their portable business. Actually, in my more than eight years of experience working with partners, I have found that the opposite is true. The great majority err on being too conservative, primarily because they do not want to seem to be overstating their business to prospective firms. While there are good reasons to be conservative, you don't want to fail to properly recognize the full extent of your practice or to otherwise unfairly damage your opportunities. It also does not look good to change your numbers significantly during the process, especially if the change drops you below the minimum sought by the firm.
Third, compare the original and the prospective firms. All else being equal, clients will prefer the firm that can do a good job on its legal work at a lower cost. So if the prospective firm has better rates, and is otherwise competent to do the client's work, that is another factor in favor of portability. Other factors could include having offices in cities that are key to the client, or having strength in key areas.
Fourth, do not limit yourself to the usual type of portable business, which means active work for a client that is currently "on your desk" and can be taken with you to another firm. Portable business can also include business that is not active from a company that is not a current client of the original firm, but which would likely become active for the partner if the partner moved to the prospective firm. The company's unwillingness to work with the original firm could be because of conflicts, rates or lack of strength in a particular area - all things that could be cured if the partner joined a different firm.
In sum, portable business estimates are important. Take the time to do them correctly.