diff --git a/erpnext/patches.txt b/erpnext/patches.txt
index cee796e..0c36c9f 100644
--- a/erpnext/patches.txt
+++ b/erpnext/patches.txt
@@ -309,3 +309,4 @@
 erpnext.patches.v14_0.update_opportunity_currency_fields
 erpnext.patches.v13_0.gst_fields_for_pos_invoice
 erpnext.patches.v13_0.create_accounting_dimensions_in_pos_doctypes
+erpnext.patches.v13_0.trim_sales_invoice_custom_field_length
diff --git a/erpnext/patches/v13_0/trim_sales_invoice_custom_field_length.py b/erpnext/patches/v13_0/trim_sales_invoice_custom_field_length.py
new file mode 100644
index 0000000..fd48c0d
--- /dev/null
+++ b/erpnext/patches/v13_0/trim_sales_invoice_custom_field_length.py
@@ -0,0 +1,18 @@
+# Copyright (c) 2020, Frappe and Contributors
+# License: GNU General Public License v3. See license.txt
+
+import frappe
+
+from erpnext.regional.india.setup import create_custom_fields, get_custom_fields
+
+
+def execute():
+	company = frappe.get_all('Company', filters = {'country': 'India'})
+	if not company:
+		return
+
+	custom_fields = {
+		'Sales Invoice': get_custom_fields().get('Sales Invoice')
+	}
+
+	create_custom_fields(custom_fields, update=True)
diff --git a/erpnext/regional/india/setup.py b/erpnext/regional/india/setup.py
index a2a4a09..93cbcca 100644
--- a/erpnext/regional/india/setup.py
+++ b/erpnext/regional/india/setup.py
@@ -132,6 +132,10 @@
 		make_property_setter('Journal Entry', 'voucher_type', 'options', '\n'.join(journal_entry_types), '')
 
 def make_custom_fields(update=True):
+	custom_fields = get_custom_fields()
+	create_custom_fields(custom_fields, update=update)
+
+def get_custom_fields():
 	hsn_sac_field = dict(fieldname='gst_hsn_code', label='HSN/SAC',
 		fieldtype='Data', fetch_from='item_code.gst_hsn_code', insert_after='description',
 		allow_on_submit=1, print_hide=1, fetch_if_empty=1)
@@ -672,7 +676,8 @@
 			}
 		]
 	}
-	create_custom_fields(custom_fields, update=update)
+
+	return custom_fields
 
 def make_fixtures(company=None):
 	docs = []