diff --git a/src/mutations/createAccount.js b/src/mutations/createAccount.js
index da6deee..b3c1322 100644
--- a/src/mutations/createAccount.js
+++ b/src/mutations/createAccount.js
@@ -78,7 +78,7 @@ export default async function createAccount(context, input) {
     userId
   };
 
-  let groups = [];
+  let groups = new Set();
   let invites;
 
   // if this is the first user created overall, add them to the
@@ -87,27 +87,36 @@ export default async function createAccount(context, input) {
   if (!anyAccount) {
     const accountsManagerGroupId = await ensureAccountsManagerGroup(context);
     const systemManagerGroupId = await ensureSystemManagerGroup(context);
-    groups.push(systemManagerGroupId);
-    groups.push(accountsManagerGroupId);
+    groups.add(systemManagerGroupId);
+    groups.add(accountsManagerGroupId);
   } else {
     // if this isn't the first account see if they were invited by another user
     // find all invites for this email address, for all shops, and add to all groups
     const emailAddresses = emails.map((emailRecord) => emailRecord.address.toLowerCase());
     invites = await AccountInvites.find({ email: { $in: emailAddresses } }).toArray();
-    groups = invites.map((invite) => invite.groupId);
+    groups = invites.reduce((allGroupIds, invite) => {
+      if (invite.groupIds) {
+        invite.groupIds.forEach((groupId) => {
+          return allGroupIds.add(groupId);
+        });
+      }
+
+      if (invite.groupId) {
+        allGroupIds.add(invite.groupId);
+      }
+
+      return allGroupIds;
+    }, new Set());
   }
 
   AccountSchema.validate(account);
 
   await Accounts.insertOne(account);
 
-  for (const groupId of groups) {
-    // eslint-disable-next-line no-await-in-loop
-    await context.mutations.addAccountToGroup(context.getInternalContext(), {
-      accountId: account._id,
-      groupId
-    });
-  }
+  await context.mutations.updateGroupsForAccounts(context.getInternalContext(), {
+    accountIds: [account._id],
+    groupIds: Array.from(groups)
+  });
 
   // Delete any invites that are now finished
   if (invites) {
diff --git a/src/mutations/inviteShopMember.js b/src/mutations/inviteShopMember.js
index 078af44..ecc94f5 100644
--- a/src/mutations/inviteShopMember.js
+++ b/src/mutations/inviteShopMember.js
@@ -9,7 +9,8 @@ const { REACTION_ADMIN_PUBLIC_ACCOUNT_REGISTRATION_URL } = config;
 
 const inputSchema = new SimpleSchema({
   email: String,
-  groupId: String,
+  groupIds: Array,
+  "groupIds.$": String,
   name: String,
   shopId: String
 });
@@ -22,7 +23,7 @@ const inputSchema = new SimpleSchema({
  * @param {Object} context - GraphQL execution context
  * @param {Object} input - Necessary input for mutation. See SimpleSchema.
  * @param {String} input.shopId - shop to invite user
- * @param {String} input.groupId - groupId to invite user
+ * @param {String} input.groupIds - groupIds to invite user
  * @param {String} input.email - email of invitee
  * @param {String} input.name - name of invitee
  * @return {Promise<Object>} with boolean of found new account === true || false
@@ -33,7 +34,7 @@ export default async function inviteShopMember(context, input) {
   const { Accounts, AccountInvites, Groups, Shops } = collections;
   const {
     email,
-    groupId,
+    groupIds,
     name,
     shopId
   } = input;
@@ -45,8 +46,19 @@ export default async function inviteShopMember(context, input) {
   const shop = await Shops.findOne({ _id: shopId });
   if (!shop) throw new ReactionError("not-found", "No shop found");
 
-  const group = await Groups.findOne({ _id: groupId });
-  if (!group) throw new ReactionError("not-found", "No group found");
+  const groups = await Groups.find({
+    _id: {
+      $in: groupIds
+    }
+  }).toArray();
+
+  if (groups.length === 0) {
+    throw new ReactionError("not-found", "No groups matching the provided IDs were found");
+  }
+
+  if (groups.length !== groupIds.length) {
+    throw new ReactionError("not-found", `Could not find ${groupIds.length - groups.length} of ${groupIds.length} groups provided`)
+  }
 
   const lowercaseEmail = email.toLowerCase();
 
@@ -55,17 +67,25 @@ export default async function inviteShopMember(context, input) {
 
   if (invitedAccount) {
     // Set the account's permission group for this shop
-    await context.mutations.addAccountToGroup(context, {
-      accountId: invitedAccount._id,
-      groupId
+    await context.mutations.updateGroupsForAccounts(context, {
+      accountIds: [invitedAccount._id],
+      groupIds
     });
 
     return Accounts.findOne({ _id: invitedAccount._id });
   }
 
-  // This check is part of `addAccountToGroup` mutation for existing users. For new users,
+  const groupShopIds = groups.reduce((allShopIds, group) => {
+    if (!allShopIds.includes(group.shopId)) {
+      allShopIds.push(group.shopId);
+    }
+
+    return allShopIds;
+  }, []);
+
+  // This check is part of `updateGroupsForAccounts` mutation for existing users. For new users,
   // we do it here before creating an invite record and sending the invite email.
-  await context.validatePermissions("reaction:legacy:groups", "manage:accounts", { shopId: group.shopId });
+  await Promise.all(groupShopIds.map((groupShopId) => context.validatePermissions("reaction:legacy:groups", "manage:accounts", { shopId: groupShopId })));
 
   // Create an AccountInvites document. If a person eventually creates an account with this email address,
   // it will be automatically added to this group instead of the default group for this shop.
@@ -74,7 +94,7 @@ export default async function inviteShopMember(context, input) {
     shopId
   }, {
     $set: {
-      groupId,
+      groupIds,
       invitedByUserId: userFromContext._id
     },
     $setOnInsert: {
@@ -84,11 +104,32 @@ export default async function inviteShopMember(context, input) {
     upsert: true
   });
 
+  let formattedGroupNames = groups[0].name;
+
+  // Generate a human-readable list of group names.
+  // For example, if we have groups "test1" and "test2", `formattedGroupNames` will be "test1 and test2".
+  // If we have groups "test1", "test2" and "test3", `formattedGroupNames` will be "test1, test2 and test3".
+  if (groups.length > 1) {
+    formattedGroupNames = groups.reduce((sentence, group, index) => {
+      if (index === groups.length - 1) {
+        return `${sentence} and ${group.name}`;
+      }
+
+      if (index === 0) {
+        return group.name;
+      }
+
+      return `${sentence}, ${group.name}`;
+    }, "");
+  }
+
   // Now send them an invitation email
   const dataForEmail = {
     contactEmail: _.get(shop, "emails[0].address"),
     copyrightDate: new Date().getFullYear(),
-    groupName: _.startCase(group.name),
+    groupName: _.startCase(groups[0].name),
+    groupNames: groups.map((group) => group.name),
+    hasMultipleGroups: groups.length > 1,
     legalName: _.get(shop, "addressBook[0].company"),
     physicalAddress: {
       address: `${_.get(shop, "addressBook[0].address1")} ${_.get(shop, "addressBook[0].address2")}`,
diff --git a/src/resolvers/Mutation/inviteShopMember.js b/src/resolvers/Mutation/inviteShopMember.js
index b7f9c33..7750a08 100644
--- a/src/resolvers/Mutation/inviteShopMember.js
+++ b/src/resolvers/Mutation/inviteShopMember.js
@@ -1,3 +1,4 @@
+import ReactionError from "@reactioncommerce/reaction-error";
 import { decodeGroupOpaqueId, decodeShopOpaqueId } from "../../xforms/id.js";
 
 /**
@@ -8,7 +9,8 @@ import { decodeGroupOpaqueId, decodeShopOpaqueId } from "../../xforms/id.js";
  * @param {Object} _ - unused
  * @param {Object} args.input - an object of all mutation arguments that were sent by the client
  * @param {String} args.input.email - The email address of the person to invite
- * @param {String} args.input.groupId - The permission group for this person's new account
+ * @param {String} args.input.groupId - The permission group for this person's new account (deprecated)
+ * @param {String} args.input.groupIds - The permission groups for this person's new account
  * @param {String} args.input.name - The permission group for this person's new account
  * @param {String} args.input.shopId - The ID of the shop to which you want to invite this person
  * @param {String} [args.input.clientMutationId] - An optional string identifying the mutation call
@@ -17,12 +19,24 @@ import { decodeGroupOpaqueId, decodeShopOpaqueId } from "../../xforms/id.js";
  */
 export default async function inviteShopMember(_, { input }, context) {
   const { email, groupId, name, shopId, clientMutationId = null } = input;
-  const decodedGroupId = decodeGroupOpaqueId(groupId);
+  let { groupIds } = input;
+
+  // If user is passing both `groupId` and `groupIds`, throw an error
+  if (groupId && Array.isArray(groupIds) && groupIds.length > 0) {
+    throw new ReactionError("invalid-parameter", "Can't specify both groupId and groupIds.");
+  }
+
+  // If user is using deprecated `groupId` instead of `groupIds`, populate `groupIds`
+  if (groupId && (!Array.isArray(groupIds) || groupIds.length === 0)) {
+    groupIds = [groupId];
+  }
+
+  const decodedGroupIds = groupIds.map((groupId) => decodeGroupOpaqueId(groupId));
   const decodedShopId = decodeShopOpaqueId(shopId);
 
   const account = await context.mutations.inviteShopMember(context, {
     email,
-    groupId: decodedGroupId,
+    groupIds: decodedGroupIds,
     name,
     shopId: decodedShopId
   });
diff --git a/src/schemas/inviteShopMember.graphql b/src/schemas/inviteShopMember.graphql
index 93a17ef..366dcd5 100644
--- a/src/schemas/inviteShopMember.graphql
+++ b/src/schemas/inviteShopMember.graphql
@@ -6,8 +6,12 @@ input InviteShopMemberInput {
   "The email address of the person to invite"
   email: String!
 
-  "The permission group for this person's new account"
-  groupId: ID!
+  "The permission group for this person's new account. DEPRECATED. Use `groupIds` field instead."
+  # @deprecated isn't allowed on input fields yet. See See https://github.com/graphql/graphql-spec/pull/525
+  groupId: ID
+
+  "The permission groups for this person's new account"
+  groupIds: [ID]
 
   "The invitee's full name"
   name: String!