diff --git a/packages/core/src/systems/en-UK/long-count/parse.ts b/packages/core/src/systems/en-UK/long-count/parse.ts
index 585751d..f55152e 100644
--- a/packages/core/src/systems/en-UK/long-count/parse.ts
+++ b/packages/core/src/systems/en-UK/long-count/parse.ts
@@ -30,6 +30,12 @@ import {
 	TENS_ONES_SEPARATOR,
 	TensName,
 	THOUSAND,
+	DoParseState,
+	ParseGroupsMode,
+	ParserState,
+	parseOnes,
+	parseTenPlusOnes,
+	parseTens,
 } from '../../en/common';
 
 const FINAL_TOKEN = '' as const;
@@ -61,13 +67,6 @@ export const tokenize = (value: string) => (
 		.filter((maybeToken) => maybeToken.length > 0)
 );
 
-interface DoParseState {
-	groupNameCurrent: string;
-	millias: number[];
-	milliaIndex: number;
-	done: boolean;
-}
-
 /**
  * Deconstructs a group name token (e.g. "million", "duodecillion", etc.) to its affixes and
  * parses them.
@@ -219,50 +218,6 @@ const getGroupPlaceFromGroupName = (groupName: string) => {
 	return bigGroupPlace * BigInt(2) + (groupName.startsWith(THOUSAND) ? BigInt(1) : BigInt(0));
 };
 
-/**
- * Mode of the group parser.
- */
-enum ParseGroupsMode {
-	/**
-	 * Initial mode.
-	 */
-	INITIAL = 'initial',
-	/**
-	 * Has parsed a ones name.
-	 */
-	ONES_MODE = 'ones',
-	/**
-	 * Has parsed a tens name.
-	 */
-	TENS_MODE = 'tens',
-	/**
-	 * Has parsed a ten-plus-ones name.
-	 */
-	TEN_PLUS_ONES_MODE = 'tenPlusOnes',
-	/**
-	 * Has parsed a "hundred" token.
-	 */
-	HUNDRED_MODE = 'hundred',
-	/**
-	 * Has parsed a "thousand" or any "-illion" token.
-	 */
-	THOUSAND_MODE = 'thousand',
-	/**
-	 * Done parsing.
-	 */
-	DONE = 'done',
-}
-
-/**
- * State of the group parser.
- */
-interface ParserState {
-	lastToken?: string;
-	groups: Group[];
-	mode: ParseGroupsMode;
-	negative: boolean;
-}
-
 const parseThousand = (acc: ParserState, token: string): ParserState => {
 	const lastGroup = acc.groups.at(-1) ?? [...EMPTY_PLACE];
 
@@ -337,68 +292,6 @@ const parseFinal = (acc: ParserState): ParserState => {
 	return acc;
 };
 
-const parseOnes = (acc: ParserState, token: string): ParserState => {
-	if (acc.mode === ParseGroupsMode.THOUSAND_MODE) {
-		// Create next empty place
-		return {
-			...acc,
-			lastToken: token,
-			mode: ParseGroupsMode.ONES_MODE,
-			groups: [...acc.groups, [...EMPTY_PLACE]],
-		};
-	}
-	return {
-		...acc,
-		lastToken: token,
-		mode: ParseGroupsMode.ONES_MODE,
-	};
-};
-
-const parseTenPlusOnes = (acc: ParserState, token: string): ParserState => {
-	const tenPlusOnes = TEN_PLUS_ONES.findIndex((t) => t === token);
-	const lastGroup = acc.groups.at(-1) ?? [...EMPTY_PLACE];
-	if (acc.mode === ParseGroupsMode.THOUSAND_MODE) {
-		return {
-			...acc,
-			lastToken: token,
-			mode: ParseGroupsMode.TEN_PLUS_ONES_MODE,
-			groups: [...acc.groups, [`01${tenPlusOnes}` as GroupDigits, lastGroup[GROUP_PLACE_INDEX] - BigInt(1)]],
-		};
-	}
-
-	lastGroup[GROUP_DIGITS_INDEX] = `${lastGroup[GROUP_DIGITS_INDEX].slice(0, 1)}1${tenPlusOnes}` as GroupDigits;
-	return {
-		...acc,
-		lastToken: token,
-		mode: ParseGroupsMode.TEN_PLUS_ONES_MODE,
-		groups: [...acc.groups.slice(0, -1), lastGroup],
-	};
-};
-
-const parseTens = (acc: ParserState, token: string): ParserState => {
-	const tens = TENS.findIndex((t) => t === token);
-	const lastGroup = acc.groups.at(-1) ?? [...EMPTY_PLACE];
-	if (acc.mode === ParseGroupsMode.THOUSAND_MODE) {
-		return {
-			...acc,
-			lastToken: token,
-			mode: ParseGroupsMode.TENS_MODE,
-			groups: [...acc.groups, [`0${tens}0` as GroupDigits, lastGroup[GROUP_PLACE_INDEX] - BigInt(1)]],
-		};
-	}
-
-	lastGroup[GROUP_DIGITS_INDEX] = (
-		`${lastGroup[GROUP_DIGITS_INDEX].slice(0, 1)}${tens}${lastGroup[GROUP_DIGITS_INDEX].slice(2)}`
-	) as GroupDigits;
-
-	return {
-		...acc,
-		lastToken: token,
-		mode: ParseGroupsMode.TENS_MODE,
-		groups: [...acc.groups.slice(0, -1), lastGroup],
-	};
-};
-
 /**
  * Parses groups from a string.
  * @param tokens - The string to parse groups from.
diff --git a/packages/core/src/systems/en-US/short-count/parse.ts b/packages/core/src/systems/en-US/short-count/parse.ts
index e76c04f..53e3269 100644
--- a/packages/core/src/systems/en-US/short-count/parse.ts
+++ b/packages/core/src/systems/en-US/short-count/parse.ts
@@ -30,6 +30,12 @@ import {
 	TENS_ONES_SEPARATOR,
 	TensName,
 	THOUSAND,
+	DoParseState,
+	ParseGroupsMode,
+	ParserState,
+	parseOnes,
+	parseTens,
+	parseTenPlusOnes,
 } from '../../en/common';
 
 const FINAL_TOKEN = '' as const;
@@ -55,13 +61,6 @@ export const tokenize = (value: string) => (
 		.filter((maybeToken) => maybeToken.length > 0)
 );
 
-interface DoParseState {
-	groupNameCurrent: string;
-	millias: number[];
-	milliaIndex: number;
-	done: boolean;
-}
-
 /**
  * Deconstructs a group name token (e.g. "million", "duodecillion", etc.) to its affixes and
  * parses them.
@@ -217,50 +216,6 @@ const getGroupPlaceFromGroupName = (groupName: string) => {
 	return bigGroupPlace + BigInt(1);
 };
 
-/**
- * Mode of the group parser.
- */
-enum ParseGroupsMode {
-	/**
-	 * Initial mode.
-	 */
-	INITIAL = 'initial',
-	/**
-	 * Has parsed a ones name.
-	 */
-	ONES_MODE = 'ones',
-	/**
-	 * Has parsed a tens name.
-	 */
-	TENS_MODE = 'tens',
-	/**
-	 * Has parsed a ten-plus-ones name.
-	 */
-	TEN_PLUS_ONES_MODE = 'tenPlusOnes',
-	/**
-	 * Has parsed a "hundred" token.
-	 */
-	HUNDRED_MODE = 'hundred',
-	/**
-	 * Has parsed a "thousand" or any "-illion" token.
-	 */
-	THOUSAND_MODE = 'thousand',
-	/**
-	 * Done parsing.
-	 */
-	DONE = 'done',
-}
-
-/**
- * State of the group parser.
- */
-interface ParserState {
-	lastToken?: string;
-	groups: Group[];
-	mode: ParseGroupsMode;
-	negative: boolean;
-}
-
 const parseThousand = (acc: ParserState, token: string): ParserState => {
 	const lastGroup = acc.groups.at(-1) ?? [...EMPTY_PLACE];
 
@@ -335,68 +290,6 @@ const parseFinal = (acc: ParserState): ParserState => {
 	return acc;
 };
 
-const parseOnes = (acc: ParserState, token: string): ParserState => {
-	if (acc.mode === ParseGroupsMode.THOUSAND_MODE) {
-		// Create next empty place
-		return {
-			...acc,
-			lastToken: token,
-			mode: ParseGroupsMode.ONES_MODE,
-			groups: [...acc.groups, [...EMPTY_PLACE]],
-		};
-	}
-	return {
-		...acc,
-		lastToken: token,
-		mode: ParseGroupsMode.ONES_MODE,
-	};
-};
-
-const parseTenPlusOnes = (acc: ParserState, token: string): ParserState => {
-	const tenPlusOnes = TEN_PLUS_ONES.findIndex((t) => t === token);
-	const lastGroup = acc.groups.at(-1) ?? [...EMPTY_PLACE];
-	if (acc.mode === ParseGroupsMode.THOUSAND_MODE) {
-		return {
-			...acc,
-			lastToken: token,
-			mode: ParseGroupsMode.TEN_PLUS_ONES_MODE,
-			groups: [...acc.groups, [`01${tenPlusOnes}` as GroupDigits, lastGroup[GROUP_PLACE_INDEX] - BigInt(1)]],
-		};
-	}
-
-	lastGroup[GROUP_DIGITS_INDEX] = `${lastGroup[GROUP_DIGITS_INDEX].slice(0, 1)}1${tenPlusOnes}` as GroupDigits;
-	return {
-		...acc,
-		lastToken: token,
-		mode: ParseGroupsMode.TEN_PLUS_ONES_MODE,
-		groups: [...acc.groups.slice(0, -1), lastGroup],
-	};
-};
-
-const parseTens = (acc: ParserState, token: string): ParserState => {
-	const tens = TENS.findIndex((t) => t === token);
-	const lastGroup = acc.groups.at(-1) ?? [...EMPTY_PLACE];
-	if (acc.mode === ParseGroupsMode.THOUSAND_MODE) {
-		return {
-			...acc,
-			lastToken: token,
-			mode: ParseGroupsMode.TENS_MODE,
-			groups: [...acc.groups, [`0${tens}0` as GroupDigits, lastGroup[GROUP_PLACE_INDEX] - BigInt(1)]],
-		};
-	}
-
-	lastGroup[GROUP_DIGITS_INDEX] = (
-		`${lastGroup[GROUP_DIGITS_INDEX].slice(0, 1)}${tens}${lastGroup[GROUP_DIGITS_INDEX].slice(2)}`
-	) as GroupDigits;
-
-	return {
-		...acc,
-		lastToken: token,
-		mode: ParseGroupsMode.TENS_MODE,
-		groups: [...acc.groups.slice(0, -1), lastGroup],
-	};
-};
-
 /**
  * Parses groups from a string.
  * @param tokens - The string to parse groups from.
diff --git a/packages/core/src/systems/en/common.ts b/packages/core/src/systems/en/common.ts
index 30fa4ab..0126fbf 100644
--- a/packages/core/src/systems/en/common.ts
+++ b/packages/core/src/systems/en/common.ts
@@ -1,4 +1,10 @@
-import { Group, GroupPlace } from '../../common';
+import {
+	Group,
+	GROUP_DIGITS_INDEX,
+	GROUP_PLACE_INDEX,
+	GroupDigits,
+	GroupPlace,
+} from '../../common';
 
 export const GROUP_SEPARATOR = ' ' as const;
 
@@ -341,3 +347,116 @@ export const makeNegative = (s: string) => {
 	const negativePrefix = `${NEGATIVE} `;
 	return s.startsWith(negativePrefix) ? s.slice(negativePrefix.length) : `${negativePrefix}${s}`;
 };
+
+export interface DoParseState {
+	groupNameCurrent: string;
+	millias: number[];
+	milliaIndex: number;
+	done: boolean;
+}
+
+/**
+ * Mode of the group parser.
+ */
+export enum ParseGroupsMode {
+	/**
+	 * Initial mode.
+	 */
+	INITIAL = 'initial',
+	/**
+	 * Has parsed a ones name.
+	 */
+	ONES_MODE = 'ones',
+	/**
+	 * Has parsed a tens name.
+	 */
+	TENS_MODE = 'tens',
+	/**
+	 * Has parsed a ten-plus-ones name.
+	 */
+	TEN_PLUS_ONES_MODE = 'tenPlusOnes',
+	/**
+	 * Has parsed a "hundred" token.
+	 */
+	HUNDRED_MODE = 'hundred',
+	/**
+	 * Has parsed a "thousand" or any "-illion" token.
+	 */
+	THOUSAND_MODE = 'thousand',
+	/**
+	 * Done parsing.
+	 */
+	DONE = 'done',
+}
+
+/**
+ * State of the group parser.
+ */
+export interface ParserState {
+	lastToken?: string;
+	groups: Group[];
+	mode: ParseGroupsMode;
+	negative: boolean;
+}
+
+export const parseOnes = (acc: ParserState, token: string): ParserState => {
+	if (acc.mode === ParseGroupsMode.THOUSAND_MODE) {
+		// Create next empty place
+		return {
+			...acc,
+			lastToken: token,
+			mode: ParseGroupsMode.ONES_MODE,
+			groups: [...acc.groups, [...EMPTY_PLACE]],
+		};
+	}
+	return {
+		...acc,
+		lastToken: token,
+		mode: ParseGroupsMode.ONES_MODE,
+	};
+};
+
+export const parseTenPlusOnes = (acc: ParserState, token: string): ParserState => {
+	const tenPlusOnes = TEN_PLUS_ONES.findIndex((t) => t === token);
+	const lastGroup = acc.groups.at(-1) ?? [...EMPTY_PLACE];
+	if (acc.mode === ParseGroupsMode.THOUSAND_MODE) {
+		return {
+			...acc,
+			lastToken: token,
+			mode: ParseGroupsMode.TEN_PLUS_ONES_MODE,
+			groups: [...acc.groups, [`01${tenPlusOnes}` as GroupDigits, lastGroup[GROUP_PLACE_INDEX] - BigInt(1)]],
+		};
+	}
+
+	lastGroup[GROUP_DIGITS_INDEX] = `${lastGroup[GROUP_DIGITS_INDEX].slice(0, 1)}1${tenPlusOnes}` as GroupDigits;
+	return {
+		...acc,
+		lastToken: token,
+		mode: ParseGroupsMode.TEN_PLUS_ONES_MODE,
+		groups: [...acc.groups.slice(0, -1), lastGroup],
+	};
+};
+
+export const parseTens = (acc: ParserState, token: string): ParserState => {
+	const tens = TENS.findIndex((t) => t === token);
+	const lastGroup = acc.groups.at(-1) ?? [...EMPTY_PLACE];
+	if (acc.mode === ParseGroupsMode.THOUSAND_MODE) {
+		return {
+			...acc,
+			lastToken: token,
+			mode: ParseGroupsMode.TENS_MODE,
+			groups: [...acc.groups, [`0${tens}0` as GroupDigits, lastGroup[GROUP_PLACE_INDEX] - BigInt(1)]],
+		};
+	}
+
+	lastGroup[GROUP_DIGITS_INDEX] = (
+		`${lastGroup[GROUP_DIGITS_INDEX].slice(0, 1)}${tens}${lastGroup[GROUP_DIGITS_INDEX].slice(2)}`
+	) as GroupDigits;
+
+	return {
+		...acc,
+		lastToken: token,
+		mode: ParseGroupsMode.TENS_MODE,
+		groups: [...acc.groups.slice(0, -1), lastGroup],
+	};
+};