as for Slip sheets.... for existing clients... you will have to bring up the form Slip Sheet for each client, go to Firm name and address Line 2... and right click>override> and type in correct mailing address.  For all new clients... go to Tools>edit client template>click on Slip Sheet in the Forms in use> and do the same override as mentioned above. you will probably have to do in each module..1040/1065/1120S, etc.

For Invoices, you will need to be in a client.. tools>billing>edit invoice>standard client invoice>edit.

At the top...like 2nd line

 [@CPCFirmAdr1]<@CPCFirmAdr1>  

delete  that line...then type in your mailing address...you can use the bar at top to 'center' that like the rest of your address.

then save.

Hope this helps