diff --git a/app/assets/stylesheets/components/broadcast-message.scss b/app/assets/stylesheets/components/broadcast-message.scss
index d9e51f85f..672ce5207 100644
--- a/app/assets/stylesheets/components/broadcast-message.scss
+++ b/app/assets/stylesheets/components/broadcast-message.scss
@@ -6,6 +6,7 @@
     max-width: 464px;
     box-sizing: border-box;
     padding: govuk-spacing(9) govuk-spacing(3) govuk-spacing(3) govuk-spacing(3);
+    border: solid 1px transparent; // to show it's area in high contrast mode
     background: $panel-colour;
     box-shadow: inset 0 -1px 0 0 rgba(0, 0, 0, 0.05);
     border-radius: 5px;
@@ -18,10 +19,11 @@
   &-heading {
     display: block;
     position: absolute;
-    top: 0;
-    left: 0;
+    top: -1px;
+    left: -1px;
     padding: govuk-spacing(2) + 1px govuk-spacing(3) (govuk-spacing(2) - 1px) 46px;
-    width: 100%;
+    border: solid 1px transparent; // to show it's area in high contrast mode
+    width: calc(100% + 2px); // grow to overlap wrapper's border (when combined with top and left)
     box-sizing: border-box;
     font-weight: bold;
     background: $grey-1 file-url('exclamation.svg');
diff --git a/app/assets/stylesheets/components/pill.scss b/app/assets/stylesheets/components/pill.scss
index e497852de..8ef516b31 100644
--- a/app/assets/stylesheets/components/pill.scss
+++ b/app/assets/stylesheets/components/pill.scss
@@ -122,7 +122,8 @@
 
     display: block;
     text-align: left;
-    padding: 10px govuk-spacing(3);
+    padding: 9px (govuk-spacing(3) - 1);
+    border: 1px solid transparent;
     text-align: center;
 
     &:link,
diff --git a/app/assets/stylesheets/components/textbox.scss b/app/assets/stylesheets/components/textbox.scss
index c20769caa..f9687a7ea 100644
--- a/app/assets/stylesheets/components/textbox.scss
+++ b/app/assets/stylesheets/components/textbox.scss
@@ -39,6 +39,11 @@
     padding-bottom: govuk-spacing(3);
     z-index: 10;
 
+    // transparent borders become visible in high contrast modes so set to match background
+    @media (-ms-high-contrast: active), (forced-colors: active) {
+      border-color: Canvas;
+    }
+
     .placeholder,
     .placeholder-conditional {
       color: transparent;