Western Union licenses independent agents to market and sell their money transfer services, including money orders. Purchasing a money order requires bringing funds to a Western Union agent, who then records the transaction, documents the sender and the payee and notes the money order number in case a problem arises with the transaction. Because the cash to cover the money order has already been received, it's considered a more secure form of payment than a personal check.
Agents Make the Rules
Each agent sets its own policies about the size of transactions it is willing to accept. As a result, the limit for a Western Union money order varies by location. Western Union agents aren't obligated to cash money orders either, although many will. Typically, the maximum that a Western Union agent will allow to be placed on a money order is $1,000, though some have lower maximum limits. If you need money orders for a larger amount -- if you want to use a money order to pay your rent, for example -- you can purchase multiple money orders at the maximum to cover the total. Fees for the service also vary by Western Union location and may either be a flat fee or a percentage of the dollar amount being purchased.