Yes you can.  When you are looking at a customer or vendor, on the File menu and the toolbar there is the option to Set Field Names.

You must be in single-user mode to accomplish this.

This is the same as going to Setup, Settings, [Pick your module], Names.

Be aware that internally the field name is not changed, so if you are linking to the database internally, it is still the same name as before.  If you are using Reports from the program, it will include the new name.

Thank you for your speedy response. I'm currently in multi-user mode, will me switching to single user mode while others are multi user cause them or me any issues?

By definition, you can't switch to single-user mode if others are using the file.

If you use the option on the File menu right now you will be stopped with a message if others are still in the file.  To determine which people are in the file, select File, View All Users or if you are using an older version, File, Properties.

There are 5 or 6 users currently. If I switch at a time outside of office hours with no users, change the field names then switch back to multi users will this have any negative effect on data or other ? and will the filed names remain changed?

What you are suggesting is how you have to do it.  You can make sure everyone is out of the file (lunch, end of day, before they all come in), get into single-user mode.  Make the quick change and all your reports and data screens show the new name.  It takes less than 5 minutes if you already know where to go and what you want for the field names.

Once you make the change, go back to multi-user mode and when others log in again, they have the new names automatically.  These names are system wide settings for the whole company file and all users.

Thanks again, now for the reason I want to do this. We purchase an ERP software from ECI, it's called JobBoss, a manufacturing software to aid us with our production scheduling. This software will integrate with Sage 50 transferring data back and forth, AP and AR. It needs to see a customer ID field and a vendor ID field . . . formatted with a max of 10 characters. I'm hoping by renaming the custom fields to Customer ID & one to Vendor ID they'll be able to ping each other and transfer data as needed?

Hi, I switched to single user and it didn't allow me to edit the field name by going to,  set-up, settings, names under customer & sales ? They were greyed out. Do i need to be the administrator?

I haven't checked security on this in about a decade.  I didn't think you needed sysadmin rights to make that change.  However, you may have had other data entry windows open besides the actual ledger.

Try closing all windows using the button on the toolbar and going in through Setup, Settings, Payables or Receivables, Names and see if it allows the update.

Hi Richard . . . . we did need sysadmin rights to make the change. Thank guys for all your help. We now want another software to sync with Sage via these custom field names. Would our software look for the original name of the filed, Field4 in this case or what we renamed it to? I thought I read something about the data can be used either internally or externally . . . I didn't understand what this was trying to say?

I know nothing about the method of integration your JobBoss software has with Sage 50.  It may look for the table name in the database but you would have to tell the program to use that field.  I doubt JobBoss would know that information without you telling it.

The customer Additional Info fields are in the tcusudf table and field four is called tcusudf.sUsrDfnd4.

The vendor Additional Info fields are in the tvenudf table and field four is called tvenudf.sUsrDfnd4.