Minimum quantity based on shipping

I want to set the minimum required quantity of an order based on the shipping method.

We have two shipping methods: on-site delivery and pick-up. If the customer chooses on-site delivery, then he has to order at least 5 items, but if he chooses pick-up, then he may order less than 5. Is there an extension that supports this, or how can I change the code?

If you used Item-Based Shipping, you could create an On-Site rate that is only offered on carts with 5 or more items, and a Pick-Up method that is offered with less than 5 items. You For the On-Site rate, you would just create a rate with a cost bracket like:

From: 5, To: 99999, Charge: 10.00

or whatever your shipping cost is.

That did the trick! Thanks