I found this somewhat workaround in google groups.

http://groups.google.com/groups?hl=en&lr=&ie=UTF-
8&threadm=101901c4a5a5%2490dd36e0%24a601280a%
40phx.gbl&rnum=1&prev=/groups%3Fq%3Dmicrosoft%2Bmoney%
2B2005%2Bimport%2Binvoice%26hl%3Den%26lr%3D%26ie%3 DUTF-8%
26selm%3D101901c4a5a5%252490dd36e0%2524a601280a%
2540phx.gbl%26rnum%3D1

COPY OF GOOGLE POST
-------------------
I found a work around to add my custom invoice to MNY
2005 since this
version is so BUGGY.

Go to this folder:
C:\Documents and Settings\All Users\Application
Data\Microsoft\Money\14.0\Invoice
The HTM files are the preset invoices. You can open them
in IE.
Look for your custom invoice, it should be here even if
it doesn't show up
in money 05. It will be called usrxxxxx.htm (xxxx =
random numbers)

Open it in Notepad, copy the content, open a pre-made
invoice file, paste
the content and save.
(Back up the pre-made invoice in case you want to use it)

Now in Money one of the pre-made invoice will be your
custom made invoice.

and don't forget to call msft support so they know this
is a problem....

- quote -

I upgraded from Money 2k4 Small Business (SB) to Money 2k5
SB last week - and my custom invoice is gone! I've seen
some other posts on this but nothing definitive (yes,
I'ver searched first; TechNet too.)

Fortunately, I said a copy of the invoices to a .INV file
(when I had the portrait/landscape fiasco in 2k4). SO, I
go into Money Invoice Designer and import it. Comes in
fine, and I see my invoice - but when I save it an exit,
the invoice STILL isn't there.

In Money, I tried to import the .INV file, and I get an
error saying it can't import items made before 2002 - wtf?

Do we have a definitive answer on this? I use Money SB to
actually BILL my clients and I can't without my invoice.
Well, I suppose I *can* using a generic/default
invoice...but c'mon, how professional is THAT going to
look?

Hans
OneNetworkTech Consulting
http://www.OneNetworkTech.com
"Harness the power of ONE."