diff --git a/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/address-form/address-form.tsx b/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/address-form/address-form.tsx
index 84b45a8df64..b054ca2ca96 100644
--- a/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/address-form/address-form.tsx
+++ b/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/address-form/address-form.tsx
@@ -1,7 +1,6 @@
 /**
  * External dependencies
  */
-import PropTypes from 'prop-types';
 import { ValidatedTextInput } from '@woocommerce/base-components/text-input';
 import {
 	BillingCountryInput,
@@ -241,14 +240,4 @@ const AddressForm = ( {
 	);
 };
 
-AddressForm.propTypes = {
-	onChange: PropTypes.func.isRequired,
-	values: PropTypes.object.isRequired,
-	fields: PropTypes.arrayOf(
-		PropTypes.oneOf( Object.keys( defaultAddressFields ) )
-	),
-	fieldConfig: PropTypes.object,
-	type: PropTypes.oneOf( [ 'billing', 'shipping' ] ),
-};
-
 export default withInstanceId( AddressForm );
diff --git a/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/form-step/index.js b/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/form-step/index.tsx
similarity index 77%
rename from plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/form-step/index.js
rename to plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/form-step/index.tsx
index 09a94e6eebc..7897bb6bb02 100644
--- a/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/form-step/index.js
+++ b/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/form-step/index.tsx
@@ -2,7 +2,6 @@
  * External dependencies
  */
 import classnames from 'classnames';
-import PropTypes from 'prop-types';
 import Title from '@woocommerce/base-components/title';
 
 /**
@@ -10,7 +9,12 @@ import Title from '@woocommerce/base-components/title';
  */
 import './style.scss';
 
-const StepHeading = ( { title, stepHeadingContent } ) => (
+interface StepHeadingProps {
+	title: string;
+	stepHeadingContent?: JSX.Element;
+}
+
+const StepHeading = ( { title, stepHeadingContent }: StepHeadingProps ) => (
 	<div className="wc-block-components-checkout-step__heading">
 		<Title
 			aria-hidden="true"
@@ -27,6 +31,18 @@ const StepHeading = ( { title, stepHeadingContent } ) => (
 	</div>
 );
 
+interface FormStepProps {
+	id?: string;
+	className?: string;
+	title?: string;
+	legend?: string;
+	description?: string;
+	children?: React.ReactNode;
+	disabled?: boolean;
+	showStepNumber?: boolean;
+	stepHeadingContent?: () => JSX.Element | undefined;
+}
+
 const FormStep = ( {
 	id,
 	className,
@@ -36,8 +52,8 @@ const FormStep = ( {
 	children,
 	disabled = false,
 	showStepNumber = true,
-	stepHeadingContent = () => {},
-} ) => {
+	stepHeadingContent = () => undefined,
+}: FormStepProps ): JSX.Element => {
 	// If the form step doesn't have a legend or title, render a <div> instead
 	// of a <fieldset>.
 	const Element = legend || title ? 'fieldset' : 'div';
@@ -80,16 +96,4 @@ const FormStep = ( {
 	);
 };
 
-FormStep.propTypes = {
-	id: PropTypes.string,
-	className: PropTypes.string,
-	title: PropTypes.string,
-	description: PropTypes.string,
-	children: PropTypes.node,
-	showStepNumber: PropTypes.bool,
-	stepHeadingContent: PropTypes.func,
-	disabled: PropTypes.bool,
-	legend: PropTypes.string,
-};
-
 export default FormStep;
diff --git a/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/order-summary/index.js b/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/order-summary/index.tsx
similarity index 78%
rename from plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/order-summary/index.js
rename to plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/order-summary/index.tsx
index f9d8a5327e6..435bf0adc14 100644
--- a/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/order-summary/index.js
+++ b/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/order-summary/index.tsx
@@ -2,17 +2,23 @@
  * External dependencies
  */
 import { __ } from '@wordpress/i18n';
-import PropTypes from 'prop-types';
 import { useContainerWidthContext } from '@woocommerce/base-context';
 import { Panel } from '@woocommerce/blocks-checkout';
+import type { CartItem } from '@woocommerce/types';
 
 /**
  * Internal dependencies
  */
-import OrderSummaryItem from './order-summary-item.js';
+import OrderSummaryItem from './order-summary-item';
 import './style.scss';
 
-const OrderSummary = ( { cartItems = [] } ) => {
+interface OrderSummaryProps {
+	cartItems: CartItem[];
+}
+
+const OrderSummary = ( {
+	cartItems = [],
+}: OrderSummaryProps ): null | JSX.Element => {
 	const { isLarge, hasContainerWidth } = useContainerWidthContext();
 
 	if ( ! hasContainerWidth ) {
@@ -45,10 +51,4 @@ const OrderSummary = ( { cartItems = [] } ) => {
 	);
 };
 
-OrderSummary.propTypes = {
-	cartItems: PropTypes.arrayOf(
-		PropTypes.shape( { key: PropTypes.string.isRequired } )
-	),
-};
-
 export default OrderSummary;
diff --git a/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/order-summary/order-summary-item.js b/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/order-summary/order-summary-item.tsx
similarity index 88%
rename from plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/order-summary/order-summary-item.js
rename to plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/order-summary/order-summary-item.tsx
index e427d663da8..c11a16eb2a4 100644
--- a/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/order-summary/order-summary-item.js
+++ b/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/order-summary/order-summary-item.tsx
@@ -14,11 +14,11 @@ import {
 	__experimentalApplyCheckoutFilter,
 	mustContain,
 } from '@woocommerce/blocks-checkout';
-import PropTypes from 'prop-types';
 import Dinero from 'dinero.js';
 import { getSetting } from '@woocommerce/settings';
 import { useMemo } from '@wordpress/element';
 import { useStoreCart } from '@woocommerce/base-context/hooks';
+import { CartItem, isString } from '@woocommerce/types';
 
 /**
  * Internal dependencies
@@ -28,9 +28,14 @@ import ProductImage from '../product-image';
 import ProductLowStockBadge from '../product-low-stock-badge';
 import ProductMetadata from '../product-metadata';
 
-const productPriceValidation = ( value ) => mustContain( value, '<price/>' );
+const productPriceValidation = ( value: string ): true | never =>
+	mustContain( value, '<price/>' );
 
-const OrderSummaryItem = ( { cartItem } ) => {
+interface OrderSummaryProps {
+	cartItem: CartItem;
+}
+
+const OrderSummaryItem = ( { cartItem }: OrderSummaryProps ): JSX.Element => {
 	const {
 		images,
 		low_stock_remaining: lowStockRemaining,
@@ -72,13 +77,17 @@ const OrderSummaryItem = ( { cartItem } ) => {
 
 	const regularPriceSingle = Dinero( {
 		amount: parseInt( prices.raw_prices.regular_price, 10 ),
-		precision: parseInt( prices.raw_prices.precision, 10 ),
+		precision: isString( prices.raw_prices.precision )
+			? parseInt( prices.raw_prices.precision, 10 )
+			: prices.raw_prices.precision,
 	} )
 		.convertPrecision( priceCurrency.minorUnit )
 		.getAmount();
 	const priceSingle = Dinero( {
 		amount: parseInt( prices.raw_prices.price, 10 ),
-		precision: parseInt( prices.raw_prices.precision, 10 ),
+		precision: isString( prices.raw_prices.precision )
+			? parseInt( prices.raw_prices.precision, 10 )
+			: prices.raw_prices.precision,
 	} )
 		.convertPrecision( priceCurrency.minorUnit )
 		.getAmount();
@@ -126,7 +135,7 @@ const OrderSummaryItem = ( { cartItem } ) => {
 			<div className="wc-block-components-order-summary-item__image">
 				<div className="wc-block-components-order-summary-item__quantity">
 					<Label
-						label={ quantity }
+						label={ quantity.toString() }
 						screenReaderLabel={ sprintf(
 							/* translators: %d number of products of the same type in the cart */
 							_n(
@@ -203,20 +212,4 @@ const OrderSummaryItem = ( { cartItem } ) => {
 	);
 };
 
-OrderSummaryItem.propTypes = {
-	cartItems: PropTypes.shape( {
-		images: PropTypes.array,
-		low_stock_remaining: PropTypes.number,
-		name: PropTypes.string.isRequired,
-		permalink: PropTypes.string,
-		prices: PropTypes.shape( {
-			price: PropTypes.string,
-			regular_price: PropTypes.string,
-		} ),
-		quantity: PropTypes.number,
-		summary: PropTypes.string,
-		variation: PropTypes.array,
-	} ),
-};
-
 export default OrderSummaryItem;
diff --git a/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/return-to-cart-button/index.js b/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/return-to-cart-button/index.tsx
similarity index 78%
rename from plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/return-to-cart-button/index.js
rename to plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/return-to-cart-button/index.tsx
index 2d7bb2cec98..eaf09544141 100644
--- a/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/return-to-cart-button/index.js
+++ b/plugins/woocommerce-blocks/assets/js/base/components/cart-checkout/return-to-cart-button/index.tsx
@@ -10,7 +10,13 @@ import { Icon, arrowBack } from '@woocommerce/icons';
  */
 import './style.scss';
 
-const ReturnToCartButton = ( { link } ) => {
+interface ReturnToCartButtonProps {
+	link?: string;
+}
+
+const ReturnToCartButton = ( {
+	link,
+}: ReturnToCartButtonProps ): JSX.Element => {
 	return (
 		<a
 			href={ link || CART_URL }
diff --git a/plugins/woocommerce-blocks/assets/js/base/components/formatted-monetary-amount/index.tsx b/plugins/woocommerce-blocks/assets/js/base/components/formatted-monetary-amount/index.tsx
index 213b665d27c..d04e5eab918 100644
--- a/plugins/woocommerce-blocks/assets/js/base/components/formatted-monetary-amount/index.tsx
+++ b/plugins/woocommerce-blocks/assets/js/base/components/formatted-monetary-amount/index.tsx
@@ -6,8 +6,8 @@ import NumberFormat, {
 	NumberFormatProps,
 } from 'react-number-format';
 import classNames from 'classnames';
-import type { Currency } from '@woocommerce/price-format';
 import type { ReactElement } from 'react';
+import type { Currency } from '@woocommerce/types';
 
 /**
  * Internal dependencies
@@ -20,6 +20,8 @@ interface FormattedMonetaryAmountProps {
 	value: number | string; // Value of money amount.
 	currency: Currency | Record< string, never >; // Currency configuration object.
 	onValueChange?: ( unit: number ) => void; // Function to call when value changes.
+	style?: React.CSSProperties;
+	renderText?: ( value: string ) => JSX.Element;
 }
 
 /**
diff --git a/plugins/woocommerce-blocks/assets/js/base/components/product-price/index.js b/plugins/woocommerce-blocks/assets/js/base/components/product-price/index.tsx
similarity index 76%
rename from plugins/woocommerce-blocks/assets/js/base/components/product-price/index.js
rename to plugins/woocommerce-blocks/assets/js/base/components/product-price/index.tsx
index 50b39572bb1..1f3b4f047d4 100644
--- a/plugins/woocommerce-blocks/assets/js/base/components/product-price/index.js
+++ b/plugins/woocommerce-blocks/assets/js/base/components/product-price/index.tsx
@@ -4,22 +4,30 @@
 import { __, sprintf } from '@wordpress/i18n';
 import FormattedMonetaryAmount from '@woocommerce/base-components/formatted-monetary-amount';
 import classNames from 'classnames';
-import PropTypes from 'prop-types';
 import { formatPrice } from '@woocommerce/price-format';
 import { createInterpolateElement } from '@wordpress/element';
+import type { Currency } from '@woocommerce/types';
 
 /**
  * Internal dependencies
  */
 import './style.scss';
 
+interface PriceRangeProps {
+	currency: Currency | Record< string, never >; // Currency configuration object;
+	maxPrice: string | number;
+	minPrice: string | number;
+	priceClassName?: string;
+	priceStyle?: React.CSSProperties;
+}
+
 const PriceRange = ( {
 	currency,
 	maxPrice,
 	minPrice,
 	priceClassName,
 	priceStyle,
-} ) => {
+}: PriceRangeProps ) => {
 	return (
 		<>
 			<span className="screen-reader-text">
@@ -58,6 +66,16 @@ const PriceRange = ( {
 	);
 };
 
+interface SalePriceProps {
+	currency: Currency | Record< string, never >; // Currency configuration object.
+	regularPriceClassName?: string;
+	regularPriceStyle?: Record< string, string >;
+	regularPrice: number | string;
+	priceClassName?: string;
+	priceStyle?: Record< string, string >;
+	price: number | string;
+}
+
 const SalePrice = ( {
 	currency,
 	regularPriceClassName,
@@ -66,7 +84,7 @@ const SalePrice = ( {
 	priceClassName,
 	priceStyle,
 	price,
-} ) => {
+}: SalePriceProps ) => {
 	return (
 		<>
 			<span className="screen-reader-text">
@@ -110,20 +128,35 @@ const SalePrice = ( {
 	);
 };
 
+interface ProductPriceProps {
+	align?: 'left' | 'center' | 'right';
+	className?: string;
+	currency: Currency | Record< string, never >; // Currency configuration object.
+	format: string;
+	price: number | string;
+	priceClassName?: string;
+	priceStyle?: Record< string, string >;
+	maxPrice?: number | string;
+	minPrice?: number | string;
+	regularPrice?: number | string;
+	regularPriceClassName?: string;
+	regularPriceStyle?: Record< string, string >;
+}
+
 const ProductPrice = ( {
 	align,
 	className,
 	currency,
 	format = '<price/>',
-	maxPrice = null,
-	minPrice = null,
-	price = null,
+	maxPrice,
+	minPrice,
+	price,
 	priceClassName,
 	priceStyle,
 	regularPrice,
 	regularPriceClassName,
 	regularPriceStyle,
-} ) => {
+}: ProductPriceProps ): JSX.Element => {
 	const wrapperClassName = classNames(
 		className,
 		'price',
@@ -161,7 +194,7 @@ const ProductPrice = ( {
 				regularPriceStyle={ regularPriceStyle }
 			/>
 		);
-	} else if ( minPrice !== null && maxPrice !== null ) {
+	} else if ( minPrice !== undefined && maxPrice !== undefined ) {
 		priceComponent = (
 			<PriceRange
 				currency={ currency }
@@ -171,7 +204,7 @@ const ProductPrice = ( {
 				priceStyle={ priceStyle }
 			/>
 		);
-	} else if ( price !== null ) {
+	} else if ( price ) {
 		priceComponent = (
 			<FormattedMonetaryAmount
 				className={ classNames(
@@ -194,21 +227,4 @@ const ProductPrice = ( {
 	);
 };
 
-ProductPrice.propTypes = {
-	align: PropTypes.oneOf( [ 'left', 'center', 'right' ] ),
-	className: PropTypes.string,
-	currency: PropTypes.object,
-	format: PropTypes.string,
-	price: PropTypes.oneOfType( [ PropTypes.number, PropTypes.string ] ),
-	priceClassName: PropTypes.string,
-	priceStyle: PropTypes.object,
-	// Range price props
-	maxPrice: PropTypes.oneOfType( [ PropTypes.number, PropTypes.string ] ),
-	minPrice: PropTypes.oneOfType( [ PropTypes.number, PropTypes.string ] ),
-	// On sale price props
-	regularPrice: PropTypes.oneOfType( [ PropTypes.number, PropTypes.string ] ),
-	regularPriceClassName: PropTypes.string,
-	regularPriceStyle: PropTypes.object,
-};
-
 export default ProductPrice;
diff --git a/plugins/woocommerce-blocks/assets/js/types/type-defs/cart.ts b/plugins/woocommerce-blocks/assets/js/types/type-defs/cart.ts
index ce8cbe83ed0..31d17c53fea 100644
--- a/plugins/woocommerce-blocks/assets/js/types/type-defs/cart.ts
+++ b/plugins/woocommerce-blocks/assets/js/types/type-defs/cart.ts
@@ -7,6 +7,8 @@ import {
 	ExtensionsData,
 } from './cart-response';
 
+import { ProductResponseItemData } from './product-response';
+
 export interface CurrencyInfo {
 	currency_code: string;
 	currency_symbol: string;
@@ -131,7 +133,7 @@ export interface CartItem {
 	prices: CartItemPrices;
 	totals: CartItemTotals;
 	extensions: ExtensionsData;
-	item_data: Record< string, unknown >[];
+	item_data: ProductResponseItemData[];
 }
 
 export interface CartTotalsTaxLineItem {
diff --git a/plugins/woocommerce-blocks/packages/checkout/utils/validation/index.ts b/plugins/woocommerce-blocks/packages/checkout/utils/validation/index.ts
index ad8bc638acf..d5625faff4b 100644
--- a/plugins/woocommerce-blocks/packages/checkout/utils/validation/index.ts
+++ b/plugins/woocommerce-blocks/packages/checkout/utils/validation/index.ts
@@ -9,7 +9,7 @@ import { __, sprintf } from '@wordpress/i18n';
 export const mustContain = (
 	value: string,
 	requiredValue: string
-): true | Error => {
+): true | never => {
 	if ( ! value.includes( requiredValue ) ) {
 		throw Error(
 			sprintf(