I need to let people order a product but then rather than pay give them the option of an invoice. How can I do this please

If you want all features of the payment field but do not want your users to make any payment in form, you need to add "Purchase Order" payment field in form. You may like to take a look at the following guide which should help you: https://www.jotform.com/help/460-how-to-create-payment-form-with-purchase-order

You can also add "Product List" field in form as well and do not integrate it with your merchant account. Please check the screenshot below:

Hope this helps.

Do get back to us if you have any questions.

amazing...I knew there must be an easy way, thank you