fix: updated patch, add fields only if fields are checked
diff --git a/erpnext/erpnext_integrations/doctype/taxjar_settings/taxjar_settings.py b/erpnext/erpnext_integrations/doctype/taxjar_settings/taxjar_settings.py
index c6d714b..2ee3350 100644
--- a/erpnext/erpnext_integrations/doctype/taxjar_settings/taxjar_settings.py
+++ b/erpnext/erpnext_integrations/doctype/taxjar_settings/taxjar_settings.py
@@ -4,14 +4,30 @@
 
 from __future__ import unicode_literals
 
+import json
+import os
+
 import frappe
+from frappe.custom.doctype.custom_field.custom_field import create_custom_fields
 from frappe.model.document import Document
+from frappe.permissions import add_permission, update_permission_property
 
 from erpnext.erpnext_integrations.taxjar_integration import get_client
 
 
 class TaxJarSettings(Document):
 
+	def on_update(self):
+		TAXJAR_CREATE_TRANSACTIONS = frappe.db.get_single_value("TaxJar Settings", "taxjar_create_transactions")
+		TAXJAR_CALCULATE_TAX = frappe.db.get_single_value("TaxJar Settings", "taxjar_calculate_tax")
+		TAXJAR_SANDBOX_MODE = frappe.db.get_single_value("TaxJar Settings", "is_sandbox")
+
+		if TAXJAR_CREATE_TRANSACTIONS or TAXJAR_CALCULATE_TAX or TAXJAR_SANDBOX_MODE:
+			add_product_tax_categories()
+			make_custom_fields()
+			add_permissions()
+			frappe.enqueue('erpnext.regional.united_states.setup.add_product_tax_categories', now=False)
+
 	@frappe.whitelist()
 	def update_nexus_list(self):
 		client = get_client()
@@ -21,4 +37,44 @@
 
 		self.set('nexus', [])
 		self.set('nexus', new_nexus_list)
-		self.save()
\ No newline at end of file
+		self.save()
+
+def add_product_tax_categories():
+	with open(os.path.join(os.path.dirname(__file__), 'product_tax_category_data.json'), 'r') as f:
+		tax_categories = json.loads(f.read())
+	create_tax_categories(tax_categories['categories'])
+
+def create_tax_categories(data):
+	for d in data:
+		tax_category = frappe.new_doc('Product Tax Category')
+		tax_category.description = d.get("description")
+		tax_category.product_tax_code = d.get("product_tax_code")
+		tax_category.category_name = d.get("name")
+		try:
+			tax_category.db_insert()
+		except frappe.DuplicateEntryError:
+			pass
+
+def make_custom_fields(update=True):
+	custom_fields = {
+		'Sales Invoice Item': [
+			dict(fieldname='product_tax_category', fieldtype='Link', insert_after='description', options='Product Tax Category',
+				label='Product Tax Category', fetch_from='item_code.product_tax_category'),
+			dict(fieldname='tax_collectable', fieldtype='Currency', insert_after='net_amount',
+				label='Tax Collectable', read_only=1),
+			dict(fieldname='taxable_amount', fieldtype='Currency', insert_after='tax_collectable',
+				label='Taxable Amount', read_only=1)
+		],
+		'Item': [
+			dict(fieldname='product_tax_category', fieldtype='Link', insert_after='item_group', options='Product Tax Category',
+				label='Product Tax Category')
+		]
+	}
+	create_custom_fields(custom_fields, update=update)
+
+def add_permissions():
+	doctype = "Product Tax Category"
+	for role in ('Accounts Manager', 'Accounts User', 'System Manager','Item Manager', 'Stock Manager'):
+		add_permission(doctype, role, 0)
+		update_permission_property(doctype, role, 0, 'write', 1)
+		update_permission_property(doctype, role, 0, 'create', 1)
diff --git a/erpnext/patches/v13_0/custom_fields_for_taxjar_integration.py b/erpnext/patches/v13_0/custom_fields_for_taxjar_integration.py
index eee9f11..139d8e4 100644
--- a/erpnext/patches/v13_0/custom_fields_for_taxjar_integration.py
+++ b/erpnext/patches/v13_0/custom_fields_for_taxjar_integration.py
@@ -3,12 +3,16 @@
 import frappe
 from frappe.custom.doctype.custom_field.custom_field import create_custom_fields
 
-from erpnext.regional.united_states.setup import add_permissions
+from erpnext.erpnext_integrations.doctype.taxjar_settings.taxjar_settings import add_permissions
 
 
 def execute():
+	TAXJAR_CREATE_TRANSACTIONS = frappe.db.get_single_value("TaxJar Settings", "taxjar_create_transactions")
+	TAXJAR_CALCULATE_TAX = frappe.db.get_single_value("TaxJar Settings", "taxjar_calculate_tax")
+	TAXJAR_SANDBOX_MODE = frappe.db.get_single_value("TaxJar Settings", "is_sandbox")
 	company = frappe.get_all('Company', filters = {'country': 'United States'}, fields=['name'])
-	if not company:
+
+	if not company or (not TAXJAR_CREATE_TRANSACTIONS and not TAXJAR_CALCULATE_TAX and not TAXJAR_SANDBOX_MODE):
 		return
 
 	frappe.reload_doc("regional", "doctype", "product_tax_category")
@@ -29,4 +33,4 @@
 	}
 	create_custom_fields(custom_fields, update=True)
 	add_permissions()
-	frappe.enqueue('erpnext.regional.united_states.setup.add_product_tax_categories', now=True)
+	frappe.enqueue('erpnext.erpnext_integrations.doctype.taxjar_settings.taxjar_settings.add_product_tax_categories', now=True)
diff --git a/erpnext/regional/united_states/setup.py b/erpnext/regional/united_states/setup.py
index 9c183af..cf78f92 100644
--- a/erpnext/regional/united_states/setup.py
+++ b/erpnext/regional/united_states/setup.py
@@ -14,30 +14,9 @@
 		setup_company_independent_fixtures(patch=patch)
 
 def setup_company_independent_fixtures(company=None, patch=True):
-	add_product_tax_categories()
 	make_custom_fields()
-	add_permissions()
-	frappe.enqueue('erpnext.regional.united_states.setup.add_product_tax_categories', now=False)
 	add_print_formats()
 
-# Product Tax categories imported from taxjar api
-def add_product_tax_categories():
-	with open(os.path.join(os.path.dirname(__file__), 'product_tax_category_data.json'), 'r') as f:
-		tax_categories = json.loads(f.read())
-	create_tax_categories(tax_categories['categories'])
-
-def create_tax_categories(data):
-	for d in data:
-		tax_category = frappe.new_doc('Product Tax Category')
-		tax_category.description = d.get("description")
-		tax_category.product_tax_code = d.get("product_tax_code")
-		tax_category.category_name = d.get("name")
-		try:
-			tax_category.db_insert()
-		except frappe.DuplicateEntryError:
-			pass
-
-
 def make_custom_fields(update=True):
 	custom_fields = {
 		'Supplier': [
@@ -59,29 +38,10 @@
 		'Quotation': [
 			dict(fieldname='exempt_from_sales_tax', fieldtype='Check', insert_after='taxes_and_charges',
 				label='Is customer exempted from sales tax?')
-		],
-		'Sales Invoice Item': [
-			dict(fieldname='product_tax_category', fieldtype='Link', insert_after='description', options='Product Tax Category',
-				label='Product Tax Category', fetch_from='item_code.product_tax_category'),
-			dict(fieldname='tax_collectable', fieldtype='Currency', insert_after='net_amount',
-				label='Tax Collectable', read_only=1),
-			dict(fieldname='taxable_amount', fieldtype='Currency', insert_after='tax_collectable',
-				label='Taxable Amount', read_only=1)
-		],
-		'Item': [
-			dict(fieldname='product_tax_category', fieldtype='Link', insert_after='item_group', options='Product Tax Category',
-				label='Product Tax Category')
 		]
 	}
 	create_custom_fields(custom_fields, update=update)
 
-def add_permissions():
-	doctype = "Product Tax Category"
-	for role in ('Accounts Manager', 'Accounts User', 'System Manager','Item Manager', 'Stock Manager'):
-		add_permission(doctype, role, 0)
-		update_permission_property(doctype, role, 0, 'write', 1)
-		update_permission_property(doctype, role, 0, 'create', 1)
-
 def add_print_formats():
 	frappe.reload_doc("regional", "print_format", "irs_1099_form")
 	frappe.db.set_value("Print Format", "IRS 1099 Form", "disabled", 0)