remove coupons on checkout page (WC 2.0)

I did it myself,
woocommerce/templates/checkout/form-coupon.php

just add this line

if ( $woocommerce->checkout)
	return;

This section and others are being generated from the woocommerce-hooks.php file in the plugin directory. Another way to remove this functionality from the checkout page would be to de-register the action hook being used to generate the content.

You would simply need to place the following code at the top of the form-checkout.php page (just under global $woocommerce to remove the coupon form call:

remove_action( 'woocommerce_before_checkout_form', 'woocommerce_checkout_login_form', 10 );

That should do the trick!

The above post removes the login form, not the coupon form – to do this, insert the following code in your theme’s functions.php file:

remove_action( 'woocommerce_before_checkout_form', 'woocommerce_checkout_coupon_form', 10 );

Thank you @rob01

There is an easy way to turn off Coupons from within WooCommerce

Dashboard
> WooCommerce
> Settings
> General
> Coupons
> Enable the use of Coupons (uncheck this)

Cheers