So options:-
1. pdf in landscape - horizontal
2. Download in excel
3. You can modify the customer balance report:-
Copy the file reporting/rep101.php to company/xx/reporting where xx is the company number, (0 for only one company)(after the file has been modified you will need to copy it to any other companies you require the report for)
You can now modify the report in company/xx/reporting without changing core files
Around line 130 you will see the following:-
reporting/rep101.php
130: $cols = array(0, 95, 140, 200, 250, 320, 385, 450, 515);
0, 95 is the width of the 1st column 95, 140 is the width of the 2nd column etc
Look at the report see what columns you can reduce in width and adjust accordingly, you will then have extra space for the # column.
Looking at it, column 4 (due date) can be significantly reduced also columns 5 and up a little each, but those will depend on your currency
All numbers must increase. the 515 can be changed to 550 which gives you an extra 35 for starters
With a little time and patience you should be able to increase the 2nd column width.
Try the above 1st, if you still need more width in col 2, there are further options
The FrontAccounting Wiki(Manual, examples, tips, setup info, links to accounting sites, etc) https://frontaccounting.com/fawiki/