To avoid repeating each client for every return attached to the client when running a report in Access HandiTax you need to add [Clients Only] to your client expression name.
To add [Clients Only] to your Client Expression name:
Go to Reports, Clients, Client List Abbreviated.
In the Client Expression window highlight the expression you wish to use and click Copy.
In the Copy of ... window give your expression a name and include [Clients Only] in the name e.g. #All [Clients Only] and click OK.
Run your reports in the usual manner, using the new expression you have just created.