What documentation do we need to obtain when dealing with an MSB Agent? For example: if a customer is acting as an agent for Western Union, we need to obtain a letter from W.U. confirming our customer's status as an agent. Do we need any further information from the agent and do we need copies of Western Union's BSA/AML Program as well as proof of audits?

According to the Interagency Guidance on Providing Banking Services to MSBs, there is no one size fits all answer for what you require in terms of documentation. However, documenting an agent is relatively easy.

The Guidance suggests that you get a copy of the agent's agreement with the principal; e.g. Western Union. Unfortunately some MSBs, Western Union among them, considers that agreement to be proprietary and instructs agents not to provide copies. Failing that, you go to the MSB's web site and look for its list of agents in your area. Assuming your customer is listed there, print out that page and put it in the file.