COD payment option & coupon

Hey there,

I want to disable COD payment option if customer used Coupon Code

You’ll need some custom code to make that happen – here’s a good place to get started:
https://stackoverflow.com/questions/52120053/remove-some-payment-gateways-if-any-coupon-code-is-applied-in-woocommerce

Now coupon amount is deducted from the ‘Total’. I think it should be deducted from the ‘Sub Total’. Because of this way deduction, calculate wrong total amount in “Advance or part payment options”

That’ll actually be down to how your part payment plugin is working. Our Deposits plugin uses the subtotal, for example:
https://www.woocommerce.com/products/woocommerce-deposits/

If it’s not working correctly for you, I recommend reaching out to the developer of that specific plugin.

We haven’t heard back from you in a while, so I’m going to mark this as resolved – if you have any further questions, you can start a new thread.