Anne

Few bits :

OK we seem to want to produce an invoicing system that fairly automated in a few ways, say Invoice number [increase automatically] date, address blar blar, I design and develop a few of these and many financial documents for friends and now clients I have some are extremely good even if to me a little chunky and over basic but that?s what they want, so im happy.

My call would be this :

Use and XLS not XLT, sure we can code in an XLT and save out as XLS with ease just my IMO stay with XLS.
To save the new doc is OK I would strongly looks at a way to uniquely save as the XLS each time a new invoice is produce this has caught many guy out as administration of the save as is complex, however there are fixes to this which hop around that and cause no problems.
The save to location can be built to make the directory and dump all in there this will nead hard code as possible network locations or maybe use a xls sheet called myData for dumping all the sensitive date such as last number, directory location rather that this workbook path which will only ever cause problems, the aim is no matter where you run the XLS from the save as dump to the correct X location.

The open statement to trigger is fine or can be on form / toolbox command button, I would attach strong error handling on before close to cross check the increment have increased and error trap = 1 no more or less and that the file has been save else message box the error and abort save unless click OK but the user, so all abort.

As a project like these its forever under re-view and development so can be added to at anytime so the structure and layout need planning, I have a larger project I have recently update covering lots or areas, RoyUK and Jacks web site www.excel-it.com will have loads of invoicing and finance works there for free and corporate downloads, even offering free lessons and so on ?

IF your interested please email me and ill be so very glad to dig deep and send over what I have that?s due for our web site before this months out, in short you get it first

If you want drop Jack a line and we can chew over stuff if J & R can help you more ? just let us know.

Jack

BTW I would very strongly look into the save as file name to be automated and linked / cross referenced to the invoice number as a very first job long before the design, that a promise I have loads of guys fall down here.

EDIT: gess re-read that sounds a wofferley don?t mean to be just offering advice from stuff I do, wait till you see our work, be very pleasantly surprised.