diff --git a/includes/class-modal-checkout.php b/includes/class-modal-checkout.php
index ccf83f69e..70455b3b4 100644
--- a/includes/class-modal-checkout.php
+++ b/includes/class-modal-checkout.php
@@ -77,6 +77,10 @@ final class Modal_Checkout {
 		'selectWoo',
 		// Metorik.
 		'metorik',
+		// Braintree.
+		'braintree',
+		'paypal',
+		'jetpack',
 	];
 
 	/**
@@ -106,6 +110,8 @@ final class Modal_Checkout {
 		'selectWoo',
 		// Metorik.
 		'metorik',
+		// Braintree.
+		'braintree',
 	];
 
 	/**
@@ -118,6 +124,8 @@ public static function init() {
 		add_action( 'wp', [ __CLASS__, 'process_checkout_request' ] );
 		add_action( 'wp_ajax_abandon_modal_checkout', [ __CLASS__, 'process_abandon_checkout' ] );
 		add_action( 'wp_ajax_nopriv_abandon_modal_checkout', [ __CLASS__, 'process_abandon_checkout' ] );
+		add_action( 'wp_ajax_validate_modal_checkout', [ __CLASS__, 'validate_checkout_request' ] );
+		add_action( 'wp_ajax_nopriv_validate_modal_checkout', [ __CLASS__, 'validate_checkout_request' ] );
 
 		add_filter( 'wp_redirect', [ __CLASS__, 'pass_url_param_on_redirect' ] );
 		add_filter( 'woocommerce_cart_product_cannot_be_purchased_message', [ __CLASS__, 'woocommerce_cart_product_cannot_be_purchased_message' ], 10, 2 );
@@ -377,29 +385,54 @@ function ( $item ) {
 	 * Process abandon checkout for modal.
 	 */
 	public static function process_abandon_checkout() {
-		if ( ! defined( 'DOING_AJAX' ) ) {
-			return;
-		}
-
-		if ( ! self::is_modal_checkout() ) {
+		if ( ! defined( 'DOING_AJAX' ) || ! self::is_modal_checkout() ) {
 			return;
 		}
-
 		if ( ! check_ajax_referer( 'newspack_modal_checkout_nonce' ) ) {
 			wp_send_json_error( [ 'message' => __( 'Invalid nonce.', 'newspack-blocks' ) ] );
 			wp_die();
 		}
-
 		$cart = \WC()->cart;
 		if ( $cart && ! $cart->is_empty() ) {
 			$cart->empty_cart();
 		}
 		self::reset_checkout_registration_flag();
-
 		wp_send_json_success( [ 'message' => __( 'Cart has been emptied.', 'newspack-blocks' ) ] );
 		wp_die();
 	}
 
+	/**
+	 * Validate modal checkout.
+	 */
+	public static function validate_checkout_request() {
+		if ( ! defined( 'DOING_AJAX' ) || ! self::is_modal_checkout() ) {
+			return;
+		}
+		if ( ! check_ajax_referer( 'newspack_modal_checkout_nonce' ) ) {
+			wp_send_json_error( [ 'message' => __( 'Invalid nonce.', 'newspack-blocks' ) ] );
+			wp_die();
+		}
+		// We don't want to validate payment methods at this point, so we temporarily set the cart to not need payment.
+		add_filter( 'woocommerce_cart_needs_payment', '__return_false' );
+		$checkout    = \WC()->checkout();
+		$errors      = new WP_Error();
+		$posted_data = $checkout->get_posted_data();
+		$checkout->update_session( $posted_data );
+		$checkout->validate_checkout( $posted_data, $errors );
+		remove_filter( 'woocommerce_cart_needs_payment', '__return_false' );
+		if ( $errors->get_error_codes() ) {
+			$error_messages = [];
+			foreach ( $errors->get_error_messages() as $error_message ) {
+				$error_messages[] = $error_message;
+			}
+			wp_send_json_error( [ 'messages' => $error_messages ] );
+			wp_die();
+		} else {
+			wp_send_json_success();
+			wp_die();
+		}
+	}
+
 	/**
 	 * Filter unsupported Woo Payments features.
 	 *
@@ -786,14 +819,17 @@ public static function dequeue_scripts() {
 		global $wp_scripts, $wp_styles;
 
 		$payment_gateways       = \WC()->payment_gateways->get_available_payment_gateways();
-		$allowed_gateway_assets = [];
+		$allowed_gateway_assets = array_keys( $payment_gateways );
 		if ( ! empty( $payment_gateways ) ) {
+			// Payment gateway id doesn't always match the plugin slug, so account for these cases.
 			foreach ( array_keys( $payment_gateways ) as $gateway ) {
-				$class                    = get_class( $payment_gateways[ $gateway ] );
-				$plugin_file              = ( new \ReflectionClass( $class ) )->getFileName();
-				$plugin_base              = \plugin_basename( $plugin_file );
-				$plugin_slug              = explode( '/', $plugin_base )[0];
-				$allowed_gateway_assets[] = $plugin_slug;
+				$class       = get_class( $payment_gateways[ $gateway ] );
+				$plugin_file = ( new \ReflectionClass( $class ) )->getFileName();
+				$plugin_base = \plugin_basename( $plugin_file );
+				$plugin_slug = explode( '/', $plugin_base )[0];
+				if ( ! in_array( $plugin_slug, $allowed_gateway_assets, true ) ) {
+					$allowed_gateway_assets[] = $plugin_slug;
+				}
 			}
 		}
 
@@ -839,7 +875,7 @@ public static function dequeue_scripts() {
 				}
 			}
 			foreach ( $allowed_gateway_assets as $gateway ) {
-				if ( false !== strpos( $wp_script->src, $gateway ) ) {
+				if ( false !== strpos( $handle, $gateway ) || false !== strpos( $wp_script->src, $gateway ) ) {
 					$allowed = true;
 					break;
 				}
diff --git a/src/modal-checkout/checkout.scss b/src/modal-checkout/checkout.scss
index a9323b6fa..3e5c084d9 100644
--- a/src/modal-checkout/checkout.scss
+++ b/src/modal-checkout/checkout.scss
@@ -610,6 +610,84 @@
 		}
 	}
 
+	// Braintree styles
+	li.payment_method_braintree_credit_card,
+	li.payment_method_braintree_paypal {
+		.sv-wc-payment-gateway-card-icons {
+			float: right;
+		}
+
+		.sv-wc-payment-gateway-payment-form-manage-payment-methods {
+			display: none;
+		}
+
+		& > p.form-row {
+			margin-top: var(--newspack-ui-spacer-3, 16px);
+		}
+
+		.form-row {
+			&::before,
+			&::after {
+				display: none;
+			}
+
+			input[type="radio"] + label {
+				display: inline-block;
+			}
+		}
+
+		.payment_method_braintree_credit_card,
+		.payment_method_braintree_paypal {
+			.form-row {
+				display: block;
+				margin: var(--newspack-ui-spacer-base, 8px) 0;
+				padding: 0 !important;
+
+				label {
+					font-size: var(--newspack-ui-font-size-s, 16px);
+					font-weight: 600;
+					line-height: var(--newspack-ui-line-height-s, 1.5);
+					margin: 0 0 var(--newspack-ui-spacer-base, 8px);
+				}
+
+				.wc-braintree-hosted-field-card-number {
+					margin-bottom: var(--newspack-ui-spacer-base, 8px);
+				}
+
+				&:has(label[for="wc-braintree-credit-card-context-hosted"]) {
+					margin: 0;
+				}
+
+				// Hiding the test input, since it's distracted and unneeded.
+				&:has(label[for="wc-braintree-credit-card-test-amount"]),
+				&:has(label[for="wc-braintree-paypal-test-amount"]) {
+					display: none;
+				}
+
+				// This can be done via My Account, removing the link for consistency.
+				.sv-wc-payment-gateway-payment-form-manage-payment-methods {
+					display: none;
+				}
+
+				&:has(#wc-braintree-credit-card-tokenize-payment-method),
+				&:has(#wc-braintree-paypal-tokenize-payment-method) {
+					display: grid !important;
+					gap: 0 var(--newspack-ui-spacer-base, 8px);
+					grid-template-columns: var(--newspack-ui-spacer-4, 20px) 1fr;
+
+					label {
+						font-weight: 600;
+						margin: 0;
+					}
+				}
+
+				&:last-child label {
+					margin: 0;
+				}
+			}
+		}
+	}
+
 	// Order review table.
 	.woocommerce-checkout-review-order-table {
 		th,
diff --git a/src/modal-checkout/index.js b/src/modal-checkout/index.js
index 4c4527771..0a44b6921 100644
--- a/src/modal-checkout/index.js
+++ b/src/modal-checkout/index.js
@@ -617,6 +617,8 @@ import { domReady } from './utils';
 
 					const removeFromValidation = [
 						'save_user_in_woopay',
+						'woocommerce_checkout_place_order',
+						'woocommerce-process-checkout-nonce',
 					];
 					// Serialize form and remove fields that shouldn't be included for validation.
 					const serializedForm = $form.serializeArray().filter(
@@ -624,10 +626,12 @@ import { domReady } from './utils';
 					);
 					// Add 'update totals' parameter so it just performs validation.
 					serializedForm.push( { name: 'woocommerce_checkout_update_totals', value: '1' } );
+					serializedForm.push( { name: 'action', value: 'validate_modal_checkout' } );
+					serializedForm.push( { name: '_wpnonce', value: newspackBlocksModalCheckout.checkout_nonce } );
 					// Ajax request.
 					$.ajax( {
 						type: 'POST',
-						url: wc_checkout_params.checkout_url,
+						url: newspackBlocksModalCheckout.ajax_url,
 						data: serializedForm,
 						dataType: 'html',
 						success: response => {