Jo_9865,

In an unused cell on the spreadsheet, put 1.
when you open your form, change a label's caption to the contents of this
cell.
(Don't use a textbox, use a label, as a label can't be overwritten
accidentally)

LblInvoiceNo.Caption = Range("Z99").Value

After you print and save your invoice, increment the invoice number.
Range("Z99").Value = Range("Z99").Value + 1

If you close the form and reopen it, the caption will now be the new value
of Invoice Number.
If you just clear the form, ready for the next invoice, then you'll have to
update the caption with

LblInvoiceNo.Caption = Range("Z99").Value

The value in Z99 will be saved when you close the workbook and will be ready
when you re-open it.

Henry


"jo_9865" wrote in message
...
Does anyone know of a way to automatically insert the next sequential
reference number into a form in excel.

I would like a Purchase Order number to be automatically generated so
there
is no chance of the same number being used twice. Each purchase order is
currently created on separate excel workbooks and a number is currently
entered each time.

Has anyone got any ideas as to how to solve this or is there another way
to
do this perhaps using Access?