diff --git a/CHANGELOG.md b/CHANGELOG.md
index 57a23ad32..e8a79cf1f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
 - Fix a bug: wallet tab is not shown in members dashboard
 - Fix a bug: slots duration is not shown when looking at a new availability
 - Fix a bug: user's manual URL is not up-to-date
+- Fix a bug: unable to create a subscription plan for only one group
 - Updated coveralls gem to a supported version
 
 ## v4.5.6 2020 September 1st
diff --git a/app/assets/javascripts/controllers/admin/plans.js.erb b/app/assets/javascripts/controllers/admin/plans.js.erb
index a86ab8da8..f7596be74 100644
--- a/app/assets/javascripts/controllers/admin/plans.js.erb
+++ b/app/assets/javascripts/controllers/admin/plans.js.erb
@@ -21,12 +21,20 @@
 /* COMMON CODE */
 
 class PlanController {
-  constructor ($scope, groups, prices, partners, CSRF) {
+  constructor ($scope, groups, prices, partners, CSRF, _t) {
     // protection against request forgery
     CSRF.setMetaTags();
 
     // groups list
-    $scope.groups = groups.filter(function (g) { return (g.slug !== 'admins') && !g.disabled; });
+    $scope.groups = groups
+      .filter(function (g) { return (g.slug !== 'admins') && !g.disabled; })
+      .map(e => Object.assign({}, e, { category: 'app.shared.plan.groups', id: `${e.id}` }))
+    $scope.groups.push({ id: 'all', name: 'app.shared.plan.transversal_all_groups', category: 'app.shared.plan.all' });
+
+    // dynamically translate a label if needed
+    $scope.translateLabel = function (group, prop) {
+      return group[prop] && group[prop].match(/^app\./) ? _t(group[prop]) : group[prop];
+    }
 
     // users with role 'partner', notifiables for a partner plan
     $scope.partners = partners.users;
@@ -156,7 +164,7 @@ Application.Controllers.controller('NewPlanController', ['$scope', '$uibModal',
       }
     };
 
-    return new PlanController($scope, groups, prices, partners, CSRF);
+    return new PlanController($scope, groups, prices, partners, CSRF, _t);
   }
 ]);
 
@@ -177,13 +185,13 @@ Application.Controllers.controller('EditPlanController', ['$scope', 'groups', 'p
     $scope.machines = machines;
 
     // List of groups
-    $scope.groups = groups;
+    $scope.allGroups = groups;
 
     // current form is used for edition mode
     $scope.mode = 'edition';
 
     // edited plan data
-    $scope.plan = planPromise;
+    $scope.plan = Object.assign({}, planPromise, { group_id: `${planPromise.group_id}` });
     if ($scope.plan.type === null) { $scope.plan.type = 'Plan'; }
     if ($scope.plan.disabled) { $scope.plan.disabled = 'true'; }
 
@@ -193,6 +201,11 @@ Application.Controllers.controller('EditPlanController', ['$scope', 'groups', 'p
     // HTTP method for the rest API
     $scope.method = 'PATCH';
 
+    $scope.selectedGroup = function () {
+      const group = $scope.groups.filter(g => g.id === $scope.plan.group_id);
+      return $scope.translateLabel(group[0], 'name');
+    }
+
     /**
      * If a parent plan was set ($scope.plan.parent), the prices will be copied from this parent plan into
      * the current plan prices list. Otherwise, the current plan prices will be erased.
@@ -281,6 +294,6 @@ Application.Controllers.controller('EditPlanController', ['$scope', 'groups', 'p
     };
 
     // Using the PlansController
-    return new PlanController($scope, groups, prices, partners, CSRF);
+    return new PlanController($scope, groups, prices, partners, CSRF, _t);
   }
 ]);
diff --git a/app/assets/javascripts/directives/convert_to_number.js b/app/assets/javascripts/directives/convert_to_number.js
deleted file mode 100644
index e69de29bb..000000000
diff --git a/app/assets/templates/admin/plans/_form.html.erb b/app/assets/templates/admin/plans/_form.html.erb
index c306fdee8..eeae32643 100644
--- a/app/assets/templates/admin/plans/_form.html.erb
+++ b/app/assets/templates/admin/plans/_form.html.erb
@@ -32,12 +32,19 @@
             class="form-control"
             ng-model="plan.group_id"
             required="required"
-            ng-disabled="method == 'PATCH'">
-        <option value="all" translate>{{ 'app.shared.plan.transversal_all_groups' }}</option>
-        <optgroup label="Groupes">
-            <option ng-repeat="group in groups" ng-value="group.id" ng-selected="plan.group_id == group.id">{{group.name}}</option>
-        </optgroup>
+            ng-if="method !== 'PATCH'"
+            ng-options="item.id as translateLabel(item, 'name') group by translateLabel(item, 'category') for item in groups track by item.id">
     </select>
+    <input type="text"
+           id="plan[group_id]"
+           ng-value="selectedGroup()"
+           ng-if="method == 'PATCH'"
+           class="form-control"
+           disabled />
+    <input type="hidden"
+           name="plan[group_id]"
+           ng-value="plan.group_id"
+           ng-if="method == 'PATCH'"/>
     <span class="help-block" ng-show="planForm['plan[group_id]'].$dirty && planForm['plan[group_id]'].$error.required" translate>{{ 'app.shared.plan.group_is_required' }}</span>
 </div>
 
diff --git a/app/assets/templates/admin/plans/edit.html.erb b/app/assets/templates/admin/plans/edit.html.erb
index 324f892bf..030ec72e1 100644
--- a/app/assets/templates/admin/plans/edit.html.erb
+++ b/app/assets/templates/admin/plans/edit.html.erb
@@ -48,7 +48,7 @@
               <div class="form-group col-md-6 col-lg-offset-6">
                   <input type="hidden" ng-model="plan.parent" name="plan[parent_id]" ng-value="plan.parent"/>
                   <label for="parentPlan" translate>{{ 'app.admin.plans.edit.copy_prices_from' }}</label>
-                  <select id="parentPlan" ng-options="plan.id as humanReadablePlanName(plan, groups) for plan in plans" ng-model="plan.parent" ng-change="copyPricesFromPlan()" class="form-control">
+                  <select id="parentPlan" ng-options="plan.id as humanReadablePlanName(plan, allGroups) for plan in plans" ng-model="plan.parent" ng-change="copyPricesFromPlan()" class="form-control">
                       <option value=""></option>
                   </select>
               </div>
diff --git a/config/locales/app.shared.en.yml b/config/locales/app.shared.en.yml
index c56464b19..a57521b74 100644
--- a/config/locales/app.shared.en.yml
+++ b/config/locales/app.shared.en.yml
@@ -162,6 +162,8 @@ en:
         standard: "Standard"
         type_is_required: "Type is required."
         group: "Group"
+        groups: "Groups"
+        all: "All"
         transversal_all_groups: "Transversal (all groups)"
         group_is_required: "Group is required."
         number_of_periods: "Number of periods"