diff --git a/erpnext/accounts/party.py b/erpnext/accounts/party.py
index c5963b9..3011fd6 100644
--- a/erpnext/accounts/party.py
+++ b/erpnext/accounts/party.py
@@ -192,6 +192,15 @@
 
 	return frappe.local_cache("party_account_currency", (party_type, party, company), generator)
 
+def validate_party_accounts(doc):
+	companies = []
+
+	for account in doc.get("accounts"):
+		if account.company in companies:
+			frappe.throw(_("There can only be 1 Account per Company in {0} {1}").format(doc.doctype, doc.name))
+		else:
+			companies.append(account.company)
+
 @frappe.whitelist()
 def get_due_date(posting_date, party_type, party, company):
 	"""Set Due Date = Posting Date + Credit Days"""
diff --git a/erpnext/buying/doctype/supplier/supplier.py b/erpnext/buying/doctype/supplier/supplier.py
index e3a5541..6ae0a2e 100644
--- a/erpnext/buying/doctype/supplier/supplier.py
+++ b/erpnext/buying/doctype/supplier/supplier.py
@@ -8,6 +8,7 @@
 from frappe.model.naming import make_autoname
 from erpnext.utilities.address_and_contact import load_address_and_contact
 from erpnext.utilities.transaction_base import TransactionBase
+from erpnext.accounts.party import validate_party_accounts
 
 class Supplier(TransactionBase):
 	def get_feed(self):
@@ -45,6 +46,8 @@
 			if not self.naming_series:
 				msgprint(_("Series is mandatory"), raise_exception=1)
 
+		validate_party_accounts(self)
+
 	def get_contacts(self,nm):
 		if nm:
 			contact_details =frappe.db.convert_to_lists(frappe.db.sql("select name, CONCAT(IFNULL(first_name,''),' ',IFNULL(last_name,'')),contact_no,email_id from `tabContact` where supplier = %s", nm))
diff --git a/erpnext/selling/doctype/customer/customer.py b/erpnext/selling/doctype/customer/customer.py
index bb15a3e..9e5e7bd 100644
--- a/erpnext/selling/doctype/customer/customer.py
+++ b/erpnext/selling/doctype/customer/customer.py
@@ -7,10 +7,10 @@
 from frappe import _, msgprint, throw
 import frappe.defaults
 from frappe.utils import flt
-
+from frappe.desk.reportview import build_match_conditions
 from erpnext.utilities.transaction_base import TransactionBase
 from erpnext.utilities.address_and_contact import load_address_and_contact
-from frappe.desk.reportview import build_match_conditions
+from erpnext.accounts.party import validate_party_accounts
 
 class Customer(TransactionBase):
 	def get_feed(self):
@@ -32,6 +32,7 @@
 
 	def validate(self):
 		self.flags.is_new_doc = self.is_new()
+		validate_party_accounts(self)
 
 	def update_lead_status(self):
 		if self.lead_name: