Hi Ruth,
Unfortunately I don't believe there is a simple way of doing this.
I think simplest option in this case is probably just to create the first invoice then copy it several times, changing the supplier each time.
You can copy an invoice or bill by opening it and clicking the Copy button as in the screenshot below:
https://s3-eu-west-1.amazonaws.com/uploads-eu.hipchat.com/36185/2561547/FATp66UAP0URVWe/upload.png
Alternatively, if you have many invoices to create, you could enter the invoice details on lines in a spreadsheet (using, for example, Excel) where you could easily copy them, then use the import tool Tools > Import > Invoices to bring them into Clear Books.
I hope this helps.
All the best.