diff --git a/.changeset/five-crabs-sparkle.md b/.changeset/five-crabs-sparkle.md
new file mode 100644
index 000000000..27bd25067
--- /dev/null
+++ b/.changeset/five-crabs-sparkle.md
@@ -0,0 +1,5 @@
+---
+'@guardian/commercial': patch
+---
+
+add `liveblog-top` ad sizes
diff --git a/src/core/ad-sizes.ts b/src/core/ad-sizes.ts
index 44cc5a576..e72a98fda 100644
--- a/src/core/ad-sizes.ts
+++ b/src/core/ad-sizes.ts
@@ -106,6 +106,7 @@ type SlotName =
 	| 'fronts-banner'
 	| 'im'
 	| 'inline'
+	| 'liveblog-top'
 	| 'merchandising-high'
 	| 'merchandising'
 	| 'mobile-sticky'
@@ -338,6 +339,11 @@ const slotSizeMappings = {
 			adSizes.fluid,
 		],
 	},
+	'liveblog-top': {
+		mobile: [adSizes.outOfPage, adSizes.empty, adSizes.mpu, adSizes.fluid],
+		tablet: [],
+		desktop: [],
+	},
 	'merchandising-high': {
 		mobile: [
 			adSizes.outOfPage,