diff --git a/src/pretix/control/forms/subevents.py b/src/pretix/control/forms/subevents.py
index 4b2fb3914..ef741e675 100644
--- a/src/pretix/control/forms/subevents.py
+++ b/src/pretix/control/forms/subevents.py
@@ -23,6 +23,7 @@ from datetime import datetime
 from urllib.parse import urlencode
 
 from django import forms
+from django.core.exceptions import ValidationError
 from django.forms import formset_factory
 from django.forms.utils import ErrorDict
 from django.urls import reverse
@@ -273,6 +274,13 @@ class SubEventItemForm(SubEventItemOrVariationFormMixin, forms.ModelForm):
             'available_until': SplitDateTimeField,
         }
 
+    def clean(self):
+        d = super().clean()
+        if d.get('available_from') and d.get('available_until'):
+            if d.get('available_from') > d.get('available_until'):
+                raise ValidationError(_('The end of availability should be after the start of availability.'))
+        return d
+
 
 class SubEventItemVariationForm(SubEventItemOrVariationFormMixin, forms.ModelForm):
     def __init__(self, *args, **kwargs):
@@ -293,6 +301,13 @@ class SubEventItemVariationForm(SubEventItemOrVariationFormMixin, forms.ModelFor
             'available_until': SplitDateTimeField,
         }
 
+    def clean(self):
+        d = super().clean()
+        if d.get('available_from') and d.get('available_until'):
+            if d.get('available_from') > d.get('available_until'):
+                raise ValidationError(_('The end of availability should be after the start of availability.'))
+        return d
+
 
 class BulkSubEventItemForm(SubEventItemForm):
     rel_available_from = RelativeDateTimeField(
diff --git a/src/pretix/control/templates/pretixcontrol/subevents/bulk.html b/src/pretix/control/templates/pretixcontrol/subevents/bulk.html
index e113b6abf..6b58feb5a 100644
--- a/src/pretix/control/templates/pretixcontrol/subevents/bulk.html
+++ b/src/pretix/control/templates/pretixcontrol/subevents/bulk.html
@@ -487,6 +487,7 @@
                 {% trans "These settings are optional, if you leave them empty, the default values from the product settings will be used." %}
             </p>
             {% for f in itemvar_forms %}
+                {% bootstrap_form_errors f %}
                 <div class="form-group subevent-itemvar-group">
                     <label class="col-md-3 control-label" for="id_{{ f.prefix }}-price">
                         {% if f.variation %}{{ f.item }} – {{ f.variation }}{% else %}{{ f.item }}{% endif %}
diff --git a/src/pretix/control/templates/pretixcontrol/subevents/bulk_edit.html b/src/pretix/control/templates/pretixcontrol/subevents/bulk_edit.html
index b87c73bd1..36c8d9f7d 100644
--- a/src/pretix/control/templates/pretixcontrol/subevents/bulk_edit.html
+++ b/src/pretix/control/templates/pretixcontrol/subevents/bulk_edit.html
@@ -151,6 +151,7 @@
         <fieldset>
             <legend>{% trans "Item prices" %}</legend>
             {% for f in itemvar_forms %}
+                {% bootstrap_form_errors f %}
                 <div class="form-group subevent-itemvar-group">
                     <label class="col-md-3 control-label" for="id_{{ f.prefix }}-price">
                         {% if f.variation %}{{ f.item }} – {{ f.variation }}{% else %}{{ f.item }}{% endif %}
diff --git a/src/pretix/control/templates/pretixcontrol/subevents/detail.html b/src/pretix/control/templates/pretixcontrol/subevents/detail.html
index 4ff26d0bd..715e955c2 100644
--- a/src/pretix/control/templates/pretixcontrol/subevents/detail.html
+++ b/src/pretix/control/templates/pretixcontrol/subevents/detail.html
@@ -129,6 +129,7 @@
                         {% trans "These settings are optional, if you leave them empty, the default values from the product settings will be used." %}
                     </p>
                     {% for f in itemvar_forms %}
+                        {% bootstrap_form_errors f %}
                         <div class="form-group subevent-itemvar-group">
                             <label class="col-md-3 control-label" for="id_{{ f.prefix }}-price">
                                 {% if f.variation %}{{ f.item }} – {{ f.variation }}{% else %}{{ f.item }}{% endif %}