diff --git a/erpnext/crm/doctype/campaign/campaign.py b/erpnext/crm/doctype/campaign/campaign.py
index f9834d2ccef..4953be544a5 100644
--- a/erpnext/crm/doctype/campaign/campaign.py
+++ b/erpnext/crm/doctype/campaign/campaign.py
@@ -26,25 +26,35 @@ class Campaign(Document):
 	# end: auto-generated types
 
 	def after_insert(self):
-		try:
-			mc = frappe.get_doc("UTM Campaign", self.campaign_name)
-		except frappe.DoesNotExistError:
-			mc = frappe.new_doc("UTM Campaign")
-			mc.name = self.campaign_name
-		mc.campaign_description = self.description
-		mc.crm_campaign = self.campaign_name
-		mc.save(ignore_permissions=True)
+		self.sync_utm_campaign()
 
 	def on_change(self):
-		try:
-			mc = frappe.get_doc("UTM Campaign", self.campaign_name)
-		except frappe.DoesNotExistError:
-			mc = frappe.new_doc("UTM Campaign")
-			mc.name = self.campaign_name
+		self.sync_utm_campaign()
+
+	def sync_utm_campaign(self):
+		mc = self.get_utm_campaign_mirror()
 		mc.campaign_description = self.description
-		mc.crm_campaign = self.campaign_name
+		# link by the document name, which differs from campaign_name when a naming series is used
+		mc.crm_campaign = self.name
 		mc.save(ignore_permissions=True)
 
+	def get_utm_campaign_mirror(self):
+		# the mirror already linked to this Campaign, if any (survives campaign_name edits)
+		if owned := frappe.db.get_value("UTM Campaign", {"crm_campaign": self.name}):
+			return frappe.get_doc("UTM Campaign", owned)
+
+		# reuse a same-named mirror only when it isn't already owned by another Campaign,
+		# otherwise two Campaigns sharing a display name would hijack each other's mirror
+		if frappe.db.exists("UTM Campaign", self.campaign_name):
+			same_name = frappe.get_doc("UTM Campaign", self.campaign_name)
+			if not same_name.crm_campaign or same_name.crm_campaign == self.name:
+				return same_name
+
+		# create a fresh mirror, keeping its name unique when the display name is taken
+		mc = frappe.new_doc("UTM Campaign")
+		mc.name = self.name if frappe.db.exists("UTM Campaign", self.campaign_name) else self.campaign_name
+		return mc
+
 	def autoname(self):
 		if frappe.defaults.get_global_default("campaign_naming_by") != "Naming Series":
 			self.name = self.campaign_name
diff --git a/erpnext/crm/doctype/campaign/test_campaign.py b/erpnext/crm/doctype/campaign/test_campaign.py
index 8876e640475..e3f41e9958f 100644
--- a/erpnext/crm/doctype/campaign/test_campaign.py
+++ b/erpnext/crm/doctype/campaign/test_campaign.py
@@ -1,9 +1,70 @@
-# Copyright (c) 2021, Frappe Technologies Pvt. Ltd. and Contributors
+# Copyright (c) 2026, Frappe Technologies Pvt. Ltd. and Contributors
 # See license.txt
-# import frappe
+
+import frappe
 
 from erpnext.tests.utils import ERPNextTestSuite
 
 
 class TestCampaign(ERPNextTestSuite):
-	pass
+	"""Campaign names itself from the campaign name (or a naming series) and mirrors
+	itself into a UTM Campaign."""
+
+	def setUp(self):
+		frappe.set_user("Administrator")
+
+	def make_campaign(self, **fields):
+		doc = frappe.new_doc("Campaign")
+		doc.campaign_name = fields.pop("campaign_name", f"_Test Campaign {frappe.generate_hash(length=6)}")
+		doc.update(fields)
+		return doc.insert()
+
+	def test_autoname_uses_the_campaign_name_by_default(self):
+		campaign = self.make_campaign(campaign_name="_Test Campaign Named")
+		self.assertEqual(campaign.name, "_Test Campaign Named")
+
+	def test_autoname_uses_naming_series_when_configured(self):
+		# regression: with a naming series the document name differs from campaign_name,
+		# and the UTM sync must still link back to a valid Campaign (self.name)
+		original = frappe.defaults.get_global_default("campaign_naming_by")
+		frappe.defaults.set_global_default("campaign_naming_by", "Naming Series")
+		try:
+			campaign = self.make_campaign(naming_series="SAL-CAM-.YYYY.-")
+			self.assertTrue(campaign.name.startswith("SAL-CAM-"))
+			utm = frappe.get_doc("UTM Campaign", campaign.campaign_name)
+			self.assertEqual(utm.crm_campaign, campaign.name)
+		finally:
+			frappe.defaults.set_global_default("campaign_naming_by", original or "")
+
+	def test_inserting_mirrors_into_a_utm_campaign(self):
+		campaign = self.make_campaign(campaign_name="_Test Campaign UTM", description="Spring push")
+		self.assertTrue(frappe.db.exists("UTM Campaign", campaign.campaign_name))
+		utm = frappe.get_doc("UTM Campaign", campaign.campaign_name)
+		self.assertEqual(utm.campaign_description, "Spring push")
+		self.assertEqual(utm.crm_campaign, campaign.name)
+
+	def test_editing_campaign_name_reuses_the_same_utm_campaign(self):
+		campaign = self.make_campaign(campaign_name="_Test Campaign Rename A")
+		campaign.campaign_name = "_Test Campaign Rename B"
+		campaign.save()
+		# the edit updates the existing mirror rather than creating a second one
+		mirrors = frappe.get_all("UTM Campaign", filters={"crm_campaign": campaign.name})
+		self.assertEqual(len(mirrors), 1)
+
+	def test_two_campaigns_sharing_a_name_do_not_hijack_each_others_mirror(self):
+		# a naming series lets two Campaigns share a display name; each must keep its own mirror
+		original = frappe.defaults.get_global_default("campaign_naming_by")
+		frappe.defaults.set_global_default("campaign_naming_by", "Naming Series")
+		try:
+			first = self.make_campaign(campaign_name="_Test Shared Mirror", naming_series="SAL-CAM-.YYYY.-")
+			second = self.make_campaign(campaign_name="_Test Shared Mirror", naming_series="SAL-CAM-.YYYY.-")
+		finally:
+			frappe.defaults.set_global_default("campaign_naming_by", original or "")
+
+		# the first Campaign's mirror is untouched; the second gets a distinct one
+		self.assertEqual(
+			frappe.db.get_value("UTM Campaign", "_Test Shared Mirror", "crm_campaign"), first.name
+		)
+		second_mirror = frappe.db.get_value("UTM Campaign", {"crm_campaign": second.name})
+		self.assertTrue(second_mirror)
+		self.assertNotEqual(second_mirror, "_Test Shared Mirror")