When a new lobbying firm, or individual, registers with the House, a unique ID is created for that registrant.  Each time a new client is registered for that registrant, a sequential 4 digit number is created and combined with the registrant ID to create the House ID for that client, as shown in the example below:

For example, lobbying registrant K Street Incorporated has three clients:  Constitution Group, Independence Group, and Democracy Group.  K Street Incorporated’s House ID numbers are as follows:

Notice that the first 5 digits in this example remain the same, since all three clients are registered for the same lobbying firm.  When you register a new client, you will use the first 5 digits, which is the registrant portion of your House ID.  When you file a lobbying activity report, you will use the full 9 digit House ID for each client.