The text at the bottom of invoices are set when the invoice is generated. To change this note, follow the steps below.  

On the Invoices List View, find the group of invoices you wish to edit. 

Select ‘Show Related Line Items for Found Set of Records’ from the Scripts Menu. 

Then, select ‘Troubleshooting’ from the Scripts Menu, before selecting ‘Show All Fields (Line Items). 

Scroll across to find the ‘Text 4’ column – this field contains the note text. 

Change the text in the first record, then select ‘Replace Field Contents...’ from the Records Menu. 

Double check the details in the dialog box before selecting ‘Replace’. 

The text of the note will now be changed for all records. To check the change has applied as desired, open one of the affected invoices.