Change product price and due dates based on product on the order form

[Mechanic]

Hi!

We have a few products that we charge on the first of each month. If anyone orders in the middle of a month, they will have to pay for the full month. That means if anyone orders a product on the 15th, they will be charged for the full month, even though they are using it for 15 - 30. Sort of how Hetzner charges for its servers.

WHMCS's prorata billing isn't what we are looking for. The prorata billing does not charge for the full month.

As I understand, we need to change a product's due date and price on the order form/shopping cart so clients can see the price and the billing dates on the order form.

Any help, advice, or suggestions are welcome on how we can do that. Paid dev offers are welcome, too.

[berstein]

So, if the client purchase the product on 15th, they have to pay full price; and they have to pay full price again on the 1st day of month?

I think yes, you shouldn't use WHMCS's prorata billing, so whenever the client order the product, they will get the full price.
But you will need to modify the due date on the service, and you will also need to modify the product's period in the invoice description.

My invoice item show the line like this: Product Name Placeholder (29/05/2023 - 31/05/2023)
I don't know if it's configurable by WHMCS default, but you need to change it to before the first day of the next month, since it will follow the value of the NDD/NID (haven't check which one to be exact) of the service.
Default prorata product probably will shows the 15th of this month and 15th of the next month (assuming client purchased it on the 15th)

Edited May 29, 2023 by berstein
Wrong invoice item period