diff --git a/includes/class-wc-cart-totals.php b/includes/class-wc-cart-totals.php
index a12fa3ffd45..f0933c69471 100644
--- a/includes/class-wc-cart-totals.php
+++ b/includes/class-wc-cart-totals.php
@@ -110,11 +110,10 @@ final class WC_Cart_Totals {
 	 *
 	 * @since 3.2.0
 	 * @param object $cart Cart object to calculate totals for.
-	 * @param object $customer Customer who owns this cart.
 	 */
-	public function __construct( &$cart = null, &$customer = null ) {
+	public function __construct( &$cart = null ) {
 		$this->object        = $cart;
-		$this->calculate_tax = wc_tax_enabled() && ! $customer->get_is_vat_exempt();
+		$this->calculate_tax = wc_tax_enabled() && ! $cart->get_customer()->get_is_vat_exempt();
 
 		if ( is_a( $cart, 'WC_Cart' ) ) {
 			$this->calculate();
@@ -233,7 +232,7 @@ final class WC_Cart_Totals {
 			$fee->total  = wc_add_number_precision_deep( $fee->object->amount );
 
 			if ( $this->calculate_tax && $fee->object->taxable ) {
-				$fee->taxes     = WC_Tax::calc_tax( $fee->total, WC_Tax::get_rates( $fee->object->tax_class, $this->customer ), false );
+				$fee->taxes     = WC_Tax::calc_tax( $fee->total, WC_Tax::get_rates( $fee->object->tax_class, $this->object->get_customer() ), false );
 				$fee->total_tax = array_sum( $fee->taxes );
 
 				if ( ! $this->round_at_subtotal() ) {
@@ -321,7 +320,7 @@ final class WC_Cart_Totals {
 	 */
 	protected function get_item_tax_rates( $item ) {
 		$tax_class = $item->product->get_tax_class();
-		return isset( $this->item_tax_rates[ $tax_class ] ) ? $this->item_tax_rates[ $tax_class ] : $this->item_tax_rates[ $tax_class ] = WC_Tax::get_rates( $item->product->get_tax_class(), $this->customer );
+		return isset( $this->item_tax_rates[ $tax_class ] ) ? $this->item_tax_rates[ $tax_class ] : $this->item_tax_rates[ $tax_class ] = WC_Tax::get_rates( $item->product->get_tax_class(), $this->object->get_customer() );
 	}
 
 	/**
@@ -492,10 +491,10 @@ final class WC_Cart_Totals {
 	protected function calculate_discounts() {
 		$this->set_coupons();
 
-		$discounts = new WC_Discounts( $this->items );
+		$discounts = new WC_Discounts( $this->object );
 
 		foreach ( $this->coupons as $coupon ) {
-			$discounts->apply_coupon( $coupon );
+			$discounts->apply_discount( $coupon );
 		}
 
 		$this->discount_totals           = $discounts->get_discounts( true );
@@ -514,6 +513,18 @@ final class WC_Cart_Totals {
 
 		$applied_coupons                           = $discounts->get_applied_coupons();
 		$this->object->coupon_discount_amounts     = wp_list_pluck( $applied_coupons, 'discount' );
+
+
+
+
+
+
+
+
+
+
+
+
 		$this->object->coupon_discount_tax_amounts = wp_list_pluck( $applied_coupons, 'discount_tax' );
 	}
 
diff --git a/includes/class-wc-cart.php b/includes/class-wc-cart.php
index 3db24df3ed9..31bdcd1dd3a 100644
--- a/includes/class-wc-cart.php
+++ b/includes/class-wc-cart.php
@@ -1098,6 +1098,16 @@ class WC_Cart {
 		return ( $first_item_subtotal < $second_item_subtotal ) ? 1 : -1;
 	}
 
+	/**
+	 * Get cart's owner.
+	 *
+	 * @since  3.2.0
+	 * @return WC_Customer
+	 */
+	public function get_customer() {
+		return WC()->customer;
+	}
+
 	/**
 	 * Calculate totals for the items in the cart.
 	 */
@@ -1396,7 +1406,7 @@ class WC_Cart {
 			}
 
 			// VAT exemption done at this point - so all totals are correct before exemption
-			if ( WC()->customer->get_is_vat_exempt() ) {
+			if ( $this->get_customer()->get_is_vat_exempt() ) {
 				$this->remove_taxes();
 			}
 
@@ -1412,7 +1422,7 @@ class WC_Cart {
 			$this->tax_total = WC_Tax::get_tax_total( $this->taxes );
 
 			// VAT exemption done at this point - so all totals are correct before exemption
-			if ( WC()->customer->get_is_vat_exempt() ) {
+			if ( $this->get_customer()->get_is_vat_exempt() ) {
 				$this->remove_taxes();
 			}
 		}
@@ -1533,12 +1543,12 @@ class WC_Cart {
 						'ID' => get_current_user_id(),
 					),
 					'destination'     => array(
-						'country'   => WC()->customer->get_shipping_country(),
-						'state'     => WC()->customer->get_shipping_state(),
-						'postcode'  => WC()->customer->get_shipping_postcode(),
-						'city'      => WC()->customer->get_shipping_city(),
-						'address'   => WC()->customer->get_shipping_address(),
-						'address_2' => WC()->customer->get_shipping_address_2(),
+						'country'   => $this->get_customer()->get_shipping_country(),
+						'state'     => $this->get_customer()->get_shipping_state(),
+						'postcode'  => $this->get_customer()->get_shipping_postcode(),
+						'city'      => $this->get_customer()->get_shipping_city(),
+						'address'   => $this->get_customer()->get_shipping_address(),
+						'address_2' => $this->get_customer()->get_shipping_address_2(),
 					),
 					'cart_subtotal'       => $this->get_displayed_subtotal(),
 				),
@@ -1596,8 +1606,8 @@ class WC_Cart {
 		}
 
 		if ( 'yes' === get_option( 'woocommerce_shipping_cost_requires_address' ) ) {
-			if ( ! WC()->customer->has_calculated_shipping() ) {
-				if ( ! WC()->customer->get_shipping_country() || ( ! WC()->customer->get_shipping_state() && ! WC()->customer->get_shipping_postcode() ) ) {
+			if ( ! $this->get_customer()->has_calculated_shipping() ) {
+				if ( ! $this->get_customer()->get_shipping_country() || ( ! $this->get_customer()->get_shipping_state() && ! $this->get_customer()->get_shipping_postcode() ) ) {
 					return false;
 				}
 			}
diff --git a/includes/class-wc-coupon.php b/includes/class-wc-coupon.php
index f1746d1d48b..0fda8c44e2e 100644
--- a/includes/class-wc-coupon.php
+++ b/includes/class-wc-coupon.php
@@ -753,6 +753,8 @@ class WC_Coupon extends WC_Legacy_Coupon {
 			$this->error_message = $valid->get_error_message();
 			return false;
 		}
+
+		return $valid;
 	}
 
 	/**
diff --git a/includes/class-wc-discount.php b/includes/class-wc-discount.php
index af4b1c6e42e..3db04cd7712 100644
--- a/includes/class-wc-discount.php
+++ b/includes/class-wc-discount.php
@@ -4,11 +4,9 @@ if ( ! defined( 'ABSPATH' ) ) {
 }
 
 /**
- * A single discount.
+ * A discount.
  *
- * Represents a fixed or percent based discount at cart level. Extended by cart
- * and order discounts since they share the same logic for things like tax
- * calculation.
+ * Represents a fixed, percent or coupon based discount calculated by WC_Discounts class.
  *
  * @author  Automattic
  * @package WooCommerce/Classes
@@ -23,9 +21,11 @@ class WC_Discount extends WC_Data {
 	 * @var array
 	 */
 	protected $data = array(
+		'coupon_code' => '',
+		'discounts' => array(), // Array of discounts. Keys for item ids, values for the discount amount.
 		'amount'        => 0,
 		'discount'      => 0,
-		'discount_type' => 'fixed_cart',
+		'type' => 'fixed',
 	);
 
 	/**
@@ -37,6 +37,15 @@ class WC_Discount extends WC_Data {
 		return ( $this->get_discount_type() === $type || ( is_array( $type ) && in_array( $this->get_discount_type(), $type ) ) );
 	}
 
+	/**
+	 * Valid discount types.
+	 *
+	 * @return array
+	 */
+	protected function get_valid_discount_types() {
+		return array( 'fixed', 'percent', 'coupon' );
+	}
+
 	/**
 	 * Prefix for action and filter hooks on data.
 	 *
@@ -95,8 +104,8 @@ class WC_Discount extends WC_Data {
 	 * @param  string $context
 	 * @return string
 	 */
-	public function get_discount_type( $context = 'view' ) {
-		return $this->get_prop( 'discount_type', $context );
+	public function get_type( $context = 'view' ) {
+		return $this->get_prop( 'type', $context );
 	}
 
 	/**
@@ -105,11 +114,11 @@ class WC_Discount extends WC_Data {
 	 * @param  string $discount_type
 	 * @throws WC_Data_Exception
 	 */
-	public function set_discount_type( $discount_type ) {
-		if ( ! in_array( $discount_type, array( 'percent', 'fixed_cart' ) ) ) {
-			$this->error( 'coupon_invalid_discount_type', __( 'Invalid discount type', 'woocommerce' ) );
+	public function set_type( $discount_type ) {
+		if ( ! in_array( $discount_type, $this->get_valid_discount_types() ) ) {
+			$this->error( 'invalid_discount_type', __( 'Invalid discount type', 'woocommerce' ) );
 		}
-		$this->set_prop( 'discount_type', $discount_type );
+		$this->set_prop( 'type', $discount_type );
 	}
 
 	/**
@@ -130,11 +139,6 @@ class WC_Discount extends WC_Data {
 		return $this->get_prop( 'discount', $context );
 	}
 
-	/**
-	 * Array of negative taxes. @todo should this be here?
-	 */
-	public function set_taxes() {}
-
 	/**
 	 * Calculates the amount of negative tax to apply for this discount, since
 	 * discounts are applied before tax.
diff --git a/includes/class-wc-discounts.php b/includes/class-wc-discounts.php
index eccf714061a..ee3fba3ca8e 100644
--- a/includes/class-wc-discounts.php
+++ b/includes/class-wc-discounts.php
@@ -27,7 +27,7 @@ class WC_Discounts {
 	/**
 	 * An array of discounts which have been applied to items.
 	 *
-	 * @var array
+	 * @var WC_Discount[]
 	 */
 	protected $discounts = array();
 
@@ -48,10 +48,40 @@ class WC_Discounts {
 	/**
 	 * Constructor.
 	 *
-	 * @param array $items Items to discount.
+	 * @param array $object Cart or order object.
 	 */
-	public function __construct( $items = array() ) {
-		$this->set_items( $items );
+	public function __construct( $object = array() ) {
+		if ( is_a( $object, 'WC_Cart' ) ) {
+			$this->set_items_from_cart( $object );
+		} else {
+			// @todo accept order objects.
+		}
+	}
+
+	/**
+	 * Normalise cart/order items which will be discounted.
+	 *
+	 * @since 3.2.0
+	 * @param array $cart Cart object.
+	 */
+	public function set_items_from_cart( $cart ) {
+		$this->items = array();
+
+		foreach ( $cart->get_cart() as $key => $cart_item ) {
+			$item                = new stdClass();
+			$item->key           = $key;
+			$item->object        = $cart_item;
+			$item->product       = $cart_item['data'];
+			$item->quantity      = $cart_item['quantity'];
+			$item->price         = wc_add_number_precision_deep( $item->product->get_price() ) * $item->quantity;
+			$item->tax_class     = $item->product->get_tax_class();
+			$item->tax_rates     = WC_Tax::get_rates( $item->tax_class, $cart->get_customer() );
+			$this->items[ $key ] = $item;
+		}
+
+		uasort( $this->items, array( $this, 'sort_by_price' ) );
+
+		$this->discounts = array_merge( array_fill_keys( array_keys( $this->items ), 0 ), $this->discounts );
 	}
 
 	/**
@@ -84,7 +114,7 @@ class WC_Discounts {
 	 */
 	public function get_discounts( $in_cents = false ) {
 
-		$discounts = $in_cents ? $this->discounts : wc_remove_number_precision_deep ( $this->discounts );
+		$discounts = $in_cents ? $this->discounts : wc_remove_number_precision_deep( $this->discounts );
 
 		$manual = array();
 		foreach ( $this->manual_discounts as $manual_discount ) {
@@ -132,35 +162,45 @@ class WC_Discounts {
 	}
 
 	/**
-	 * Set cart/order items which will be discounted.
+	 * Apply a discount to all items.
 	 *
-	 * @since 3.2.0
-	 * @param array $items List items.
-	 */
-	public function set_items( $items ) {
-		$this->items           = array();
-		$this->discounts       = array();
-		$this->applied_coupons = array();
-
-		if ( ! empty( $items ) && is_array( $items ) ) {
-			foreach ( $items as $key => $item ) {
-				$this->items[ $key ]        = $item;
-				$this->items[ $key ]->key   = $key;
-				$this->items[ $key ]->price = $item->subtotal;
-			}
-			$this->discounts = array_fill_keys( array_keys( $items ), 0 );
-		}
-
-		uasort( $this->items, array( $this, 'sort_by_price' ) );
-	}
-
-	/**
-	 * Allows a discount to be applied to the items programmatically without a coupon.
-	 *
-	 * @param  string $raw_discount Discount amount either fixed or percentage.
-	 * @return int discounted amount in cents.
+	 * @param  string|object $raw_discount Accepts a string (fixed or percent discounts), WC_Discount object, or WC_Coupon object.
+	 * @return bool|WP_Error True if applied or WP_Error instance in failure.
 	 */
 	public function apply_discount( $raw_discount ) {
+		if ( is_a( $raw_discount, 'WC_Coupon' ) ) {
+			return $this->apply_coupon( $raw_discount );
+		}
+
+		$discount = false;
+
+		if ( is_a( $raw_discount, 'WC_Discount' ) ) {
+			$discount = $raw_discount;
+		} elseif ( strstr( $raw_discount, '%' ) ) {
+			$discount = new WC_Discount;
+			$discount->set_type( 'percent' );
+			$discount->set_amount( trim( $raw_discount, '%' ) );
+		} elseif ( 0 < absint( $raw_discount ) ) {
+			$discount = new WC_Discount;
+			$discount->set_type( 'fixed' );
+			$discount->set_amount( absint( $raw_discount ) );
+		}
+
+		if ( ! $discount ) {
+			return new WP_Error( 'invalid_coupon', __( 'Invalid discount', 'woocommerce' ) );
+		}
+
+
+
+
+
+
+
+
+
+
+
+
 		// Get total item cost after any extra discounts.
 		$total_to_discount = 0;
 
@@ -214,11 +254,7 @@ class WC_Discounts {
 	 * @param  WC_Coupon $coupon Coupon object being applied to the items.
 	 * @return bool|WP_Error True if applied or WP_Error instance in failure.
 	 */
-	public function apply_coupon( $coupon ) {
-		if ( ! is_a( $coupon, 'WC_Coupon' ) ) {
-			return false;
-		}
-
+	protected function apply_coupon( $coupon ) {
 		$is_coupon_valid = $this->is_coupon_valid( $coupon );
 
 		if ( is_wp_error( $is_coupon_valid ) ) {
diff --git a/tests/unit-tests/discounts/discounts.php b/tests/unit-tests/discounts/discounts.php
index 95ffee1cdac..e8e4b2a7389 100644
--- a/tests/unit-tests/discounts/discounts.php
+++ b/tests/unit-tests/discounts/discounts.php
@@ -6,38 +6,10 @@
  */
 class WC_Tests_Discounts extends WC_Unit_Test_Case {
 
-	protected function get_items_for_discounts_class() {
-		$items     = array();
-		$precision = pow( 10, wc_get_price_decimals() );
-		foreach ( WC()->cart->get_cart() as $cart_item_key => $cart_item ) {
-			$item                          = (object) array(
-				'key'                => '',
-				'quantity'           => 0,
-				'price'              => 0,
-				'product'            => false,
-				'price_includes_tax' => wc_prices_include_tax(),
-				'subtotal'           => 0,
-				'subtotal_tax'       => 0,
-				'subtotal_taxes'     => array(),
-				'total'              => 0,
-				'total_tax'          => 0,
-				'taxes'              => array(),
-				'discounted_price'   => 0,
-			);
-			$item->object            = $cart_item;
-			$item->quantity          = $cart_item['quantity'];
-			$item->subtotal          = $cart_item['data']->get_price() * $precision * $cart_item['quantity'];
-			$item->product           = $cart_item['data'];
-			$item->tax_rates         = WC_Tax::get_rates( $item->product->get_tax_class() );
-			$items[ $cart_item_key ] = $item;
-		}
-		return $items;
-	}
-
 	/**
 	 * Test get and set items.
 	 */
-	public function test_get_set_items() {
+	public function test_get_set_items_from_cart() {
 		// Create dummy product - price will be 10
 		$product = WC_Helper_Product::create_simple_product();
 
@@ -52,22 +24,22 @@ class WC_Tests_Discounts extends WC_Unit_Test_Case {
 
 		// Test setting items to the cart.
 		$discounts = new WC_Discounts();
-		$discounts->set_items( $this->get_items_for_discounts_class() );
+		$discounts->set_items_from_cart( WC()->cart );
 		$this->assertEquals( 1, count( $discounts->get_items() ) );
 
 		// Test setting items to an order.
 		$discounts = new WC_Discounts();
-		$discounts->set_items( $this->get_items_for_discounts_class() );
+		$discounts->set_items_from_cart( WC()->cart );
 		$this->assertEquals( 1, count( $discounts->get_items() ) );
 
 		// Empty array of items.
 		$discounts = new WC_Discounts();
-		$discounts->set_items( array() );
+		$discounts->set_items_from_cart( array() );
 		$this->assertEquals( array(), $discounts->get_items() );
 
 		// Invalid items.
 		$discounts = new WC_Discounts();
-		$discounts->set_items( false );
+		$discounts->set_items_from_cart( false );
 		$this->assertEquals( array(), $discounts->get_items() );
 
 		// Cleanup.
@@ -83,14 +55,14 @@ class WC_Tests_Discounts extends WC_Unit_Test_Case {
 		$discounts = new WC_Discounts();
 		$product   = WC_Helper_Product::create_simple_product();
 		WC()->cart->add_to_cart( $product->get_id(), 1 );
-		$discounts->set_items( $this->get_items_for_discounts_class() );
+		$discounts->set_items_from_cart( WC()->cart );
 
 		// Test applying multiple coupons and getting totals.
 		$coupon = WC_Helper_Coupon::create_coupon( 'test' );
 		$coupon->set_amount( 50 );
 		$coupon->set_discount_type( 'percent' );
 		$coupon->save();
-		$discounts->apply_coupon( $coupon );
+		$discounts->apply_discount( $coupon );
 
 		$this->assertEquals( array( 'test' => array( 'discount' => 5, 'discount_tax' => 0 ) ), $discounts->get_applied_coupons() );
 
@@ -99,11 +71,11 @@ class WC_Tests_Discounts extends WC_Unit_Test_Case {
 		$coupon2->set_amount( 50 );
 		$coupon2->set_discount_type( 'percent' );
 		$coupon->save();
-		$discounts->apply_coupon( $coupon2 );
+		$discounts->apply_discount( $coupon2 );
 
 		$this->assertEquals( array( 'test' => array( 'discount' => 5, 'discount_tax' => 0 ), 'test2' => array( 'discount' => 2.50, 'discount_tax' => 0 ) ), $discounts->get_applied_coupons() );
 
-		$discounts->apply_coupon( $coupon );
+		$discounts->apply_discount( $coupon );
 		$this->assertEquals( array( 'test' => array( 'discount' => 6.25, 'discount_tax' => 0 ), 'test2' => array( 'discount' => 2.50, 'discount_tax' => 0 ) ), $discounts->get_applied_coupons() );
 
 		// Test different coupon types.
@@ -112,14 +84,14 @@ class WC_Tests_Discounts extends WC_Unit_Test_Case {
 		$coupon->set_discount_type( 'fixed_product' );
 		$coupon->set_amount( 2 );
 		$coupon->save();
-		$discounts->set_items( $this->get_items_for_discounts_class() );
-		$discounts->apply_coupon( $coupon );
+		$discounts->set_items_from_cart( WC()->cart );
+		$discounts->apply_discount( $coupon );
 		$this->assertEquals( array( 'test' => array( 'discount' => 4, 'discount_tax' => 0 ) ), $discounts->get_applied_coupons() );
 
 		$coupon->set_discount_type( 'fixed_cart' );
 		$coupon->save();
-		$discounts->set_items( $this->get_items_for_discounts_class() );
-		$discounts->apply_coupon( $coupon );
+		$discounts->set_items_from_cart( WC()->cart );
+		$discounts->apply_discount( $coupon );
 		$this->assertEquals( array( 'test' => array( 'discount' => 2, 'discount_tax' => 0 ) ), $discounts->get_applied_coupons() );
 
 		// Cleanup.
@@ -146,20 +118,20 @@ class WC_Tests_Discounts extends WC_Unit_Test_Case {
 
 		// Apply a percent discount.
 		$coupon->set_discount_type( 'percent' );
-		$discounts->set_items( $this->get_items_for_discounts_class() );
-		$discounts->apply_coupon( $coupon );
+		$discounts->set_items_from_cart( WC()->cart );
+		$discounts->apply_discount( $coupon );
 		$this->assertEquals( 9, $discounts->get_discounted_price( current( $discounts->get_items() ) ) );
 
 		// Apply a fixed cart coupon.
 		$coupon->set_discount_type( 'fixed_cart' );
-		$discounts->set_items( $this->get_items_for_discounts_class() );
-		$discounts->apply_coupon( $coupon );
+		$discounts->set_items_from_cart( WC()->cart );
+		$discounts->apply_discount( $coupon );
 		$this->assertEquals( 0, $discounts->get_discounted_price( current( $discounts->get_items() ) ) );
 
 		// Apply a fixed product coupon.
 		$coupon->set_discount_type( 'fixed_product' );
-		$discounts->set_items( $this->get_items_for_discounts_class() );
-		$discounts->apply_coupon( $coupon );
+		$discounts->set_items_from_cart( WC()->cart );
+		$discounts->apply_discount( $coupon );
 		$this->assertEquals( 0, $discounts->get_discounted_price( current( $discounts->get_items() ) ) );
 
 		// Cleanup.
@@ -431,11 +403,11 @@ class WC_Tests_Discounts extends WC_Unit_Test_Case {
 				$products[] = $product;
 			}
 
-			$discounts->set_items( $this->get_items_for_discounts_class() );
+			$discounts->set_items_from_cart( WC()->cart );
 
 			foreach ( $test['coupons'] as $coupon_props ) {
 				$coupon->set_props( $coupon_props );
-				$discounts->apply_coupon( $coupon );
+				$discounts->apply_discount( $coupon );
 			}
 
 			$this->assertEquals( $test['expected_total_discount'], array_sum( $discounts->get_discounts() ), 'Test case ' . $test_index . ' failed (' . print_r( $test, true ) . ' - ' . print_r( $discounts->get_discounts(), true ) . ')' );
@@ -497,7 +469,7 @@ class WC_Tests_Discounts extends WC_Unit_Test_Case {
 		WC()->cart->add_to_cart( $product2->get_id(), 1 );
 
 		$discounts = new WC_Discounts();
-		$discounts->set_items( $this->get_items_for_discounts_class() );
+		$discounts->set_items_from_cart( WC()->cart );
 
 		$discounts->apply_discount( '50%' );
 		$all_discounts = $discounts->get_discounts();
@@ -510,7 +482,7 @@ class WC_Tests_Discounts extends WC_Unit_Test_Case {
 
 		// Test fixed discounts.
 		$discounts = new WC_Discounts();
-		$discounts->set_items( $this->get_items_for_discounts_class() );
+		$discounts->set_items_from_cart( WC()->cart );
 
 		$discounts->apply_discount( '5' );
 		$all_discounts = $discounts->get_discounts();