diff --git a/lib/utils/url-utils.js b/lib/utils/url-utils.js
index d1f6954ab..6325aa08c 100644
--- a/lib/utils/url-utils.js
+++ b/lib/utils/url-utils.js
@@ -1,87 +1,98 @@
 // @flow
 
 import urlParseLax from 'url-parse-lax';
 
 import { locallyUniqueThreadIDRegex } from '../shared/thread-utils';
 
 export type URLInfo = {
   +year?: number,
   +month?: number, // 1-indexed
   +verify?: string,
   +calendar?: boolean,
   +chat?: boolean,
   +apps?: boolean,
   +thread?: string,
   +settings?: 'account' | 'danger-zone',
+  +threadCreation?: boolean,
+  +selectedUserList?: $ReadOnlyArray<string>,
   ...
 };
 
 // We use groups to capture parts of the URL and any changes
 // to regexes must be reflected in infoFromURL.
 const yearRegex = new RegExp('(/|^)year/([0-9]+)(/|$)', 'i');
 const monthRegex = new RegExp('(/|^)month/([0-9]+)(/|$)', 'i');
 const threadRegex = new RegExp('(/|^)thread/([0-9]+)(/|$)', 'i');
 const verifyRegex = new RegExp('(/|^)verify/([a-f0-9]+)(/|$)', 'i');
 const calendarRegex = new RegExp('(/|^)calendar(/|$)', 'i');
 const chatRegex = new RegExp('(/|^)chat(/|$)', 'i');
 const appsRegex = new RegExp('(/|^)apps(/|$)', 'i');
 const accountSettingsRegex = new RegExp('(/|^)settings/account(/|$)', 'i');
 const dangerZoneRegex = new RegExp('(/|^)settings/danger-zone(/|$)', 'i');
 const threadPendingRegex = new RegExp(
   `(/|^)thread/(${locallyUniqueThreadIDRegex})(/|$)`,
   'i',
 );
+const threadCreationRegex = new RegExp(
+  '(/|^)thread/new(/([0-9]+([+][0-9]+)*))?(/|$)',
+  'i',
+);
 
 function infoFromURL(url: string): URLInfo {
   const yearMatches = yearRegex.exec(url);
   const monthMatches = monthRegex.exec(url);
   const threadMatches = threadRegex.exec(url);
   const verifyMatches = verifyRegex.exec(url);
   const calendarTest = calendarRegex.test(url);
   const chatTest = chatRegex.test(url);
   const appsTest = appsRegex.test(url);
   const accountSettingsTest = accountSettingsRegex.test(url);
   const dangerZoneTest = dangerZoneRegex.test(url);
   const threadPendingMatches = threadPendingRegex.exec(url);
+  const threadCreateMatches = threadCreationRegex.exec(url);
 
   const returnObj = {};
   if (yearMatches) {
     returnObj.year = parseInt(yearMatches[2], 10);
   }
   if (monthMatches) {
     const month = parseInt(monthMatches[2], 10);
     if (month < 1 || month > 12) {
       throw new Error('invalid_month');
     }
     returnObj.month = month;
   }
   if (threadMatches) {
     returnObj.thread = threadMatches[2];
   }
   if (threadPendingMatches) {
     returnObj.thread = threadPendingMatches[2];
   }
+  if (threadCreateMatches) {
+    returnObj.threadCreation = true;
+    returnObj.selectedUserList = threadCreateMatches[3]?.split('+') ?? [];
+  }
   if (verifyMatches) {
     returnObj.verify = verifyMatches[2];
   }
   if (calendarTest) {
     returnObj.calendar = true;
   } else if (chatTest) {
     returnObj.chat = true;
   } else if (appsTest) {
     returnObj.apps = true;
   } else if (accountSettingsTest) {
     returnObj.settings = 'account';
   } else if (dangerZoneTest) {
     returnObj.settings = 'danger-zone';
   }
   return returnObj;
 }
 
 function normalizeURL(url: string): string {
   return urlParseLax(url).href;
 }
 
 const setURLPrefix = 'SET_URL_PREFIX';
 
 export { infoFromURL, normalizeURL, setURLPrefix };
diff --git a/web/types/nav-types.js b/web/types/nav-types.js
index b7645b59c..78cb59311 100644
--- a/web/types/nav-types.js
+++ b/web/types/nav-types.js
@@ -1,18 +1,22 @@
 // @flow
 
 import type { BaseNavInfo } from 'lib/types/nav-types';
 import type { ThreadInfo } from 'lib/types/thread-types';
 
 export type NavigationTab = 'calendar' | 'chat' | 'apps' | 'settings';
 
 export type NavigationSettingsSection = 'account' | 'danger-zone';
 
+export type NavigationChatMode = 'view' | 'create';
+
 export type NavInfo = {
   ...$Exact<BaseNavInfo>,
   +tab: NavigationTab,
   +activeChatThreadID: ?string,
   +pendingThread?: ThreadInfo,
   +settingsSection?: NavigationSettingsSection,
+  +selectedUserList?: $ReadOnlyArray<string>,
+  +chatMode?: NavigationChatMode,
 };
 
 export const updateNavInfoActionType = 'UPDATE_NAV_INFO';
diff --git a/web/url-utils.js b/web/url-utils.js
index 1adb2a6f6..8812b541c 100644
--- a/web/url-utils.js
+++ b/web/url-utils.js
@@ -1,128 +1,138 @@
 // @flow
 
 import invariant from 'invariant';
 
 import {
   startDateForYearAndMonth,
   endDateForYearAndMonth,
 } from 'lib/utils/date-utils';
 import { infoFromURL } from 'lib/utils/url-utils';
 
 import { yearExtractor, monthExtractor } from './selectors/nav-selectors';
 import type { NavInfo } from './types/nav-types';
 
 function canonicalURLFromReduxState(
   navInfo: NavInfo,
   currentURL: string,
   loggedIn: boolean,
 ): string {
   const urlInfo = infoFromURL(currentURL);
   const today = new Date();
   let newURL = `/`;
 
   if (loggedIn) {
     newURL += `${navInfo.tab}/`;
     if (navInfo.tab === 'calendar') {
       const { startDate, endDate } = navInfo;
       const year = yearExtractor(startDate, endDate);
       if (urlInfo.year !== undefined) {
         invariant(
           year !== null && year !== undefined,
           `${startDate} and ${endDate} aren't in the same year`,
         );
         newURL += `year/${year}/`;
       } else if (
         year !== null &&
         year !== undefined &&
         year !== today.getFullYear()
       ) {
         newURL += `year/${year}/`;
       }
 
       const month = monthExtractor(startDate, endDate);
       if (urlInfo.month !== undefined) {
         invariant(
           month !== null && month !== undefined,
           `${startDate} and ${endDate} aren't in the same month`,
         );
         newURL += `month/${month}/`;
       } else if (
         month !== null &&
         month !== undefined &&
         month !== today.getMonth() + 1
       ) {
         newURL += `month/${month}/`;
       }
     } else if (navInfo.tab === 'chat') {
-      const activeChatThreadID = navInfo.activeChatThreadID;
-      if (activeChatThreadID) {
-        newURL += `thread/${activeChatThreadID}/`;
+      if (navInfo.chatMode === 'create') {
+        const users = navInfo.selectedUserList?.join('+') ?? '';
+        const potentiallyTrailingSlash = users.length > 0 ? '/' : '';
+        newURL += `thread/new/${users}${potentiallyTrailingSlash}`;
+      } else {
+        const activeChatThreadID = navInfo.activeChatThreadID;
+        if (activeChatThreadID) {
+          newURL += `thread/${activeChatThreadID}/`;
+        }
       }
     } else if (navInfo.tab === 'settings' && navInfo.settingsSection) {
       newURL += `${navInfo.settingsSection}/`;
     }
   }
 
   return newURL;
 }
 
 // Given a URL, this function parses out a navInfo object, leaving values as
 // default if they are unspecified.
 function navInfoFromURL(
   url: string,
   backupInfo: { now?: Date, navInfo?: NavInfo },
 ): NavInfo {
   const urlInfo = infoFromURL(url);
   const { navInfo } = backupInfo;
   const now = backupInfo.now ? backupInfo.now : new Date();
 
   let year = urlInfo.year;
   if (!year && navInfo) {
     year = yearExtractor(navInfo.startDate, navInfo.endDate);
   }
   if (!year) {
     year = now.getFullYear();
   }
 
   let month = urlInfo.month;
   if (!month && navInfo) {
     month = monthExtractor(navInfo.startDate, navInfo.endDate);
   }
   if (!month) {
     month = now.getMonth() + 1;
   }
 
   let activeChatThreadID = null;
   if (urlInfo.thread) {
     activeChatThreadID = urlInfo.thread.toString();
   } else if (navInfo) {
     activeChatThreadID = navInfo.activeChatThreadID;
   }
 
   let tab = 'chat';
   if (urlInfo.calendar) {
     tab = 'calendar';
   } else if (urlInfo.apps) {
     tab = 'apps';
   } else if (urlInfo.settings) {
     tab = 'settings';
   }
 
-  const newNavInfo = {
+  const chatMode = urlInfo.threadCreation ? 'create' : 'view';
+
+  const newNavInfo: NavInfo = {
     tab,
     startDate: startDateForYearAndMonth(year, month),
     endDate: endDateForYearAndMonth(year, month),
     activeChatThreadID,
+    chatMode,
   };
 
-  if (!urlInfo.settings) {
-    return newNavInfo;
+  if (urlInfo.selectedUserList) {
+    newNavInfo.selectedUserList = urlInfo.selectedUserList;
   }
 
-  return {
-    ...newNavInfo,
-    settingsSection: urlInfo.settings,
-  };
+  if (urlInfo.settings) {
+    newNavInfo.settingsSection = urlInfo.settings;
+  }
+
+  return newNavInfo;
 }
 
 export { canonicalURLFromReduxState, navInfoFromURL };