diff --git a/apps/timo-web/app/[locale]/(main)/settings/_hooks/account/use-settings-profile.ts b/apps/timo-web/app/[locale]/(main)/settings/_hooks/account/use-settings-profile.ts
index 8ba2db38..c07f649f 100644
--- a/apps/timo-web/app/[locale]/(main)/settings/_hooks/account/use-settings-profile.ts
+++ b/apps/timo-web/app/[locale]/(main)/settings/_hooks/account/use-settings-profile.ts
@@ -20,7 +20,7 @@ import {
   MAX_CUSTOM_TAG_COUNT,
   tagCreateDataSchema,
 } from "@/schemas/tag/tag-schema";
-import { getDefaultTagLabelKey } from "@/utils/todo/tag-label";
+import { getDefaultTagLabelKey, isDefaultTagId } from "@/utils/todo/tag-label";
 
 const LANGUAGE_REQUEST_MAP: Record<
   SettingsLanguage,
@@ -58,14 +58,13 @@ export const useSettingsProfile = () => {
   const { mutate: logoutMutate, isPending: isLoggingOut } = useLogoutMutation();
 
   const tagItems = (tagsQuery.data?.tags ?? []).map((tag) => {
-    const labelKey = tag.isDefault
-      ? getDefaultTagLabelKey(tag.tagId)
-      : undefined;
+    const isDefault = isDefaultTagId(tag.tagId);
+    const labelKey = isDefault ? getDefaultTagLabelKey(tag.tagId) : undefined;
 
     return {
       id: tag.tagId,
       label: labelKey ? tCommon(`tag.${labelKey}`) : tag.name,
-      isDefault: tag.isDefault,
+      isDefault,
     };
   });
 
diff --git a/apps/timo-web/hooks/todo-modal/common/use-tag-field.tsx b/apps/timo-web/hooks/todo-modal/common/use-tag-field.tsx
index e2cdb099..8039c8c0 100644
--- a/apps/timo-web/hooks/todo-modal/common/use-tag-field.tsx
+++ b/apps/timo-web/hooks/todo-modal/common/use-tag-field.tsx
@@ -12,7 +12,7 @@ import {
   MAX_CUSTOM_TAG_COUNT,
   tagCreateDataSchema,
 } from "@/schemas/tag/tag-schema";
-import { getDefaultTagLabelKey } from "@/utils/todo/tag-label";
+import { getDefaultTagLabelKey, isDefaultTagId } from "@/utils/todo/tag-label";
 
 export interface UseTagFieldParams<TFieldValues extends FieldValues> {
   control: Control<TFieldValues>;
@@ -63,7 +63,7 @@ export const useTagField = <TFieldValues extends FieldValues>({
     (option) => option.id === field.value,
   );
   const customTagCount = (tagsQuery.data?.tags ?? []).filter(
-    (tag) => !tag.isDefault,
+    (tag) => !isDefaultTagId(tag.tagId),
   ).length;
 
   const handleSelectTag = (label: string) => {
diff --git a/apps/timo-web/schemas/tag/tag-schema.ts b/apps/timo-web/schemas/tag/tag-schema.ts
index 60d0787b..f3bf477b 100644
--- a/apps/timo-web/schemas/tag/tag-schema.ts
+++ b/apps/timo-web/schemas/tag/tag-schema.ts
@@ -5,7 +5,6 @@ export const MAX_CUSTOM_TAG_COUNT = 4;
 export const tagSchema = z.object({
   tagId: z.number(),
   name: z.string(),
-  isDefault: z.boolean(),
 });
 
 export const tagListDataSchema = z.object({
diff --git a/apps/timo-web/utils/todo/tag-label.ts b/apps/timo-web/utils/todo/tag-label.ts
index 7454d662..f0cc3bd2 100644
--- a/apps/timo-web/utils/todo/tag-label.ts
+++ b/apps/timo-web/utils/todo/tag-label.ts
@@ -20,3 +20,6 @@ const DEFAULT_TAG_ID_TO_LABEL_KEY: Record<number, TagLabelKey> = {
 
 export const getDefaultTagLabelKey = (tagId: number): TagLabelKey | undefined =>
   DEFAULT_TAG_ID_TO_LABEL_KEY[tagId];
+
+export const isDefaultTagId = (tagId: number): boolean =>
+  getDefaultTagLabelKey(tagId) !== undefined;