Adding Multiples of the same Product to an Account

Adding Multiples of the same Product to an Account

Hello

I have added all of the products I sell, I do not wish to add each individual product with a serial number because I will not be able to report all accounts who have Product 1 etc.

My accounts may have 5 x 'Product 1', 3 x 'Product 2' etc. 
I cannot work out how to do this, I can only add 1 of each product to an account.
I was thinking of adding an attachment showing the original invoice with serial numbers, perhaps the new user interface will have better options for this?

Can you help.

Kind Regards
Trevor