diff --git a/services/web/app/src/Features/Subscription/UserFeaturesUpdater.js b/services/web/app/src/Features/Subscription/UserFeaturesUpdater.js
index cc72632b8c..f041b06137 100644
--- a/services/web/app/src/Features/Subscription/UserFeaturesUpdater.js
+++ b/services/web/app/src/Features/Subscription/UserFeaturesUpdater.js
@@ -39,6 +39,14 @@ module.exports = {
       return callback(err, featuresChanged)
     })
   },
+
+  createFeaturesOverride(userId, featuresOverride, callback) {
+    User.updateOne(
+      { _id: userId },
+      { $push: { featuresOverrides: featuresOverride } },
+      callback
+    )
+  },
 }
 
 module.exports.promises = promisifyAll(module.exports, {
diff --git a/services/web/scripts/add_feature_override.js b/services/web/scripts/add_feature_override.js
new file mode 100644
index 0000000000..a14b852a1b
--- /dev/null
+++ b/services/web/scripts/add_feature_override.js
@@ -0,0 +1,178 @@
+// Script to add feature overrides
+//
+// A feature override is appended to the user's featuresOverride list if they do
+// not already have the feature. The features are refreshed after adding the
+// override.
+//
+// If the script detects that the user would have the feature just by refreshing
+// then it skips adding the override and just refreshes the users features --
+// this is to minimise the creation of unnecessary overrides.
+//
+// Usage:
+//
+// $ node scripts/add_feature_override.js --commit --note 'text description' --expires 2022-01-01 --override JSONFILE --ids IDFILE
+//
+// --commit   do the update, remove this option for dry-run testing
+// --note     text description [optional]
+// --expires  expiry date for override [optional]
+// --skip-existing   don't create the override for users who already have the feature (e.g. via a subscription)
+//
+// IDFILE: file containing list of user ids, one per line
+// JSONFILE:  file containing JSON of the desired feature overrides e.g. {"symbolPalette": true}
+//
+// The feature override is specified with JSON to allow types to be set as string/number/boolean.
+// It is contained in a file to avoid any issues with shell quoting.
+
+const minimist = require('minimist')
+const fs = require('fs')
+const { ObjectId, waitForDb } = require('../app/src/infrastructure/mongodb')
+const pLimit = require('p-limit')
+const FeaturesUpdater = require('../app/src/Features/Subscription/FeaturesUpdater')
+const FeaturesHelper = require('../app/src/Features/Subscription/FeaturesHelper')
+const UserFeaturesUpdater = require('../app/src/Features/Subscription/UserFeaturesUpdater')
+const UserGetter = require('../app/src/Features/User/UserGetter')
+
+const processLogger = {
+  failed: [],
+  success: [],
+  skipped: [],
+  printSummary: () => {
+    console.log(
+      {
+        success: processLogger.success,
+        failed: processLogger.failed,
+        skipped: processLogger.skipped,
+      },
+      `\nDONE. ${processLogger.success.length} successful. ${processLogger.skipped.length} skipped. ${processLogger.failed.length} failed to update.`
+    )
+  },
+}
+
+function _validateUserIdList(userIds) {
+  userIds.forEach(userId => {
+    if (!ObjectId.isValid(userId))
+      throw new Error(`user ID not valid: ${userId}`)
+  })
+}
+
+async function _handleUser(userId) {
+  const user = await UserGetter.promises.getUser(userId, {
+    features: 1,
+    featuresOverrides: 1,
+  })
+  if (!user) {
+    console.log(userId, 'does not exist, failed')
+    processLogger.failed.push(userId)
+    return
+  }
+  const desiredFeatures = OVERRIDE.features
+  // Does the user have the requested features already?
+  if (
+    SKIP_EXISTING &&
+    FeaturesHelper.isFeatureSetBetter(user.features, desiredFeatures)
+  ) {
+    console.log(
+      userId,
+      `already has ${JSON.stringify(desiredFeatures)}, skipping`
+    )
+    processLogger.skipped.push(userId)
+    return
+  }
+  // Would the user have the requested feature if the features were refreshed?
+  const freshFeatures = await FeaturesUpdater.promises.computeFeatures(userId)
+  if (
+    SKIP_EXISTING &&
+    FeaturesHelper.isFeatureSetBetter(freshFeatures, desiredFeatures)
+  ) {
+    console.log(
+      userId,
+      `would have ${JSON.stringify(
+        desiredFeatures
+      )} if refreshed, skipping override`
+    )
+  } else {
+    // create the override (if not in dry-run mode)
+    if (COMMIT) {
+      await UserFeaturesUpdater.promises.createFeaturesOverride(
+        userId,
+        OVERRIDE
+      )
+    }
+  }
+
+  if (!COMMIT) {
+    // not saving features; nothing else to do
+    return
+  }
+  const refreshResult = await FeaturesUpdater.promises.refreshFeatures(
+    userId,
+    'add-feature-override-script'
+  )
+  const featureSetIncludesNewFeatures = FeaturesHelper.isFeatureSetBetter(
+    refreshResult.features,
+    desiredFeatures
+  )
+  if (featureSetIncludesNewFeatures) {
+    // features added successfully
+    processLogger.success.push(userId)
+  } else {
+    console.log('FEATURE NOT ADDED', refreshResult)
+    processLogger.failed.push(userId)
+  }
+}
+
+const argv = minimist(process.argv.slice(2))
+const CONCURRENCY = argv.async ? argv.async : 10
+const overridesFilename = argv.override
+const expires = argv.expires
+const note = argv.note
+const SKIP_EXISTING = argv['skip-existing'] || false
+const COMMIT = argv.commit !== undefined
+if (!COMMIT) {
+  console.warn('Doing dry run without --commit')
+}
+
+const idsFilename = argv.ids
+if (!idsFilename) throw new Error('missing ids list filename')
+
+const usersFile = fs.readFileSync(idsFilename, 'utf8')
+const userIds = usersFile
+  .trim()
+  .split('\n')
+  .map(id => id.trim())
+
+const overridesFile = fs.readFileSync(overridesFilename, 'utf8')
+const features = JSON.parse(overridesFile)
+const OVERRIDE = { features }
+if (note) {
+  OVERRIDE.note = note
+}
+if (expires) {
+  OVERRIDE.expiresAt = new Date(expires)
+}
+
+async function processUsers(userIds) {
+  console.log('---Starting add feature override script---')
+
+  console.log('Will update users to have', OVERRIDE)
+  console.log(
+    SKIP_EXISTING
+      ? 'Users with this feature already will be skipped'
+      : 'Every user in file will get feature override'
+  )
+
+  await waitForDb()
+
+  _validateUserIdList(userIds)
+  console.log(`---Starting to process ${userIds.length} users---`)
+
+  const limit = pLimit(CONCURRENCY)
+  await Promise.all(
+    userIds.map(userId => limit(() => _handleUser(ObjectId(userId))))
+  )
+
+  processLogger.printSummary()
+  process.exit()
+}
+
+processUsers(userIds)