diff --git a/client_add_modal.php b/client_add_modal.php
index c70976f0..f54a707a 100644
--- a/client_add_modal.php
+++ b/client_add_modal.php
@@ -297,7 +297,7 @@
                                     <div class="input-group-prepend">
                                         <span class="input-group-text"><i class="fa fa-fw fa-id-badge"></i></span>
                                     </div>
-                                    <input type="text" class="form-control" name="abbreviation" placeholder="Abbreviated name for client" maxlength="5">
+                                    <input type="text" class="form-control" name="abbreviation" placeholder="Abbreviated name for client" maxlength="5" oninput="this.value = this.value.toUpperCase()">
                                 </div>
                             </div>
 
diff --git a/client_edit_modal.php b/client_edit_modal.php
index 548afabf..0a3a87a0 100644
--- a/client_edit_modal.php
+++ b/client_edit_modal.php
@@ -190,7 +190,7 @@
                                     <div class="input-group-prepend">
                                         <span class="input-group-text"><i class="fa fa-fw fa-id-badge"></i></span>
                                     </div>
-                                    <input type="text" class="form-control" name="abbreviation" placeholder="Abbreviated name for client" value="<?php echo $client_abbreviation; ?>" maxlength="5">
+                                    <input type="text" class="form-control" name="abbreviation" placeholder="Abbreviated name for client" value="<?php echo $client_abbreviation; ?>" maxlength="5" oninput="this.value = this.value.toUpperCase()">
                                 </div>
                             </div>