diff --git a/lib/ExpensiMark.d.ts b/lib/ExpensiMark.d.ts
index 529e7b52..4a795072 100644
--- a/lib/ExpensiMark.d.ts
+++ b/lib/ExpensiMark.d.ts
@@ -8,6 +8,19 @@ declare type Rule = {
     pre?: (input: string) => string;
     post?: (input: string) => string;
 };
+
+declare type PersonalDetail = {
+    accountID: string;
+    login?: string;
+    displayName?: string
+}
+
+declare type PersonalDetails = Record<string, PersonalDetail> | {}
+
+declare type Metadata = {
+    personalDetails?: PersonalDetails
+}
+
 export default class ExpensiMark {
     rules: Rule[];
     htmlToMarkdownRules: Rule[];
@@ -56,14 +69,16 @@ export default class ExpensiMark {
      * Replaces HTML with markdown
      *
      * @param htmlString
+     * @param metadata
      */
-    htmlToMarkdown(htmlString: string): string;
+    htmlToMarkdown(htmlString: string, metadata?: Metadata): string;
     /**
      * Convert HTML to text
      *
      * @param htmlString
+     * @param metadata
      */
-    htmlToText(htmlString: string): string;
+    htmlToText(htmlString: string, metadata?: Metadata): string;
     /**
      * Modify text for Quotes replacing chevrons with html elements
      *
diff --git a/lib/ExpensiMark.js b/lib/ExpensiMark.js
index a1b01095..d50d9e8a 100644
--- a/lib/ExpensiMark.js
+++ b/lib/ExpensiMark.js
@@ -7,6 +7,12 @@ const MARKDOWN_LINK_REGEX = new RegExp(`\\[([^\\][]*(?:\\[[^\\][]*][^\\][]*)*)]\
 
 const SLACK_SPAN_NEW_LINE_TAG = '<span class="c-mrkdwn__br" data-stringify-type="paragraph-break" style="box-sizing: inherit; display: block; height: unset;"></span>';
 
+const userMentionReplacement = (openTag, accountID, closeTag, personalDetails = {}) => {
+    const user = _.get(personalDetails, accountID);
+    const displayNameOrLogin = _.get(user, 'login', '') || _.get(user, 'displayName', '');
+    return `${openTag}@${displayNameOrLogin}${closeTag}`;
+};
+
 export default class ExpensiMark {
     constructor() {
         /**
@@ -350,6 +356,16 @@ export default class ExpensiMark {
                     return `[${g4}](${email || g3})`;
                 },
             },
+            {
+                name: 'mentionUser',
+                regex: /(<mention-user accountid="(.*?)">)(<\/mention-user>)/gi,
+                replacement: userMentionReplacement,
+            },
+            {
+                name: 'mentionUser',
+                regex: /(<mention-user accountID=(.*?)>)(<\/mention-user>)/gi,
+                replacement: userMentionReplacement,
+            },
         ];
 
         /**
@@ -388,6 +404,11 @@ export default class ExpensiMark {
                 regex: /<style>.*?<\/style>/gi,
                 replacement: '',
             },
+            {
+                name: 'mentionUser',
+                regex: /(<mention-user accountID=(.*?)>)(<\/mention-user>)/gi,
+                replacement: userMentionReplacement
+            },
             {
                 name: 'stripTag',
                 regex: /(<([^>]+)>)/gi,
@@ -628,10 +649,11 @@ export default class ExpensiMark {
      * Replaces HTML with markdown
      *
      * @param {String} htmlString
-     *
+     * @param {Object} metadata
      * @returns {String}
      */
-    htmlToMarkdown(htmlString) {
+    htmlToMarkdown(htmlString, metadata = {}) {
+        const {personalDetails} = metadata;
         let generatedMarkdown = htmlString;
         const body = /<(body)(?:"[^"]*"|'[^']*'|[^'"><])*>(?:\n|\r\n)?([\s\S]*?)(?:\n|\r\n)?<\/\1>(?![^<]*(<\/pre>|<\/code>))/im;
         const parseBodyTag = generatedMarkdown.match(body);
@@ -646,6 +668,10 @@ export default class ExpensiMark {
             if (rule.pre) {
                 generatedMarkdown = rule.pre(generatedMarkdown);
             }
+            if (rule.name === 'mentionUser') {
+                generatedMarkdown = generatedMarkdown.replace(rule.regex, (match, g1, g2, g3) => rule.replacement(g1, g2, g3, personalDetails));
+                return;
+            }
             generatedMarkdown = generatedMarkdown.replace(rule.regex, rule.replacement);
         });
         return Str.htmlDecode(this.replaceBlockElementWithNewLine(generatedMarkdown));
@@ -655,12 +681,18 @@ export default class ExpensiMark {
      * Convert HTML to text
      *
      * @param {String} htmlString
+     * @param {Object} metadata
      * @returns {String}
      */
-    htmlToText(htmlString) {
+    htmlToText(htmlString, metadata = {}) {
+        const {personalDetails} = metadata;
         let replacedText = htmlString;
 
         this.htmlToTextRules.forEach((rule) => {
+            if (rule.name === 'mentionUser') {
+                replacedText = replacedText.replace(rule.regex, (match, g1, g2, g3) => rule.replacement(g1, g2, g3, personalDetails));
+                return;
+            }
             replacedText = replacedText.replace(rule.regex, rule.replacement);
         });