diff --git a/l10n_us_hr_payroll/data/state/wi_wisconsin.xml b/l10n_us_hr_payroll/data/state/wi_wisconsin.xml
index b62dc3f4..491c7311 100644
--- a/l10n_us_hr_payroll/data/state/wi_wisconsin.xml
+++ b/l10n_us_hr_payroll/data/state/wi_wisconsin.xml
@@ -7,6 +7,7 @@
         <field name="country_id" ref="base.us"/>
     </record>
     <data noupdate="1">
+        <!-- Unchanged in 2021 https://dwd.wisconsin.gov/ui/employers/taxrates.htm -->
         <record id="rule_parameter_us_wi_suta_wage_base_2020" model="hr.rule.parameter.value">
             <field name="parameter_value">14000.00</field>
             <field name="rule_parameter_id" ref="rule_parameter_us_wi_suta_wage_base"/>
@@ -15,13 +16,14 @@
     </data>
 
     <!-- Rate -->
-    <!-- Rate based on this file https://dwd.wisconsin.gov/ui/employers/taxrates.htm -->
     <record id="rule_parameter_us_wi_suta_rate" model="hr.rule.parameter">
         <field name="name">US WI Wisconsin SUTA Rate</field>
         <field name="code">us_wi_suta_rate</field>
         <field name="country_id" ref="base.us"/>
     </record>
     <data noupdate="1">
+        <!-- Rate based on this file https://dwd.wisconsin.gov/ui/employers/taxrates.htm -->
+        <!-- Unchanged in 2021 -->
         <record id="rule_parameter_us_wi_suta_rate_2020" model="hr.rule.parameter.value">
             <field name="parameter_value">3.05</field>
             <field name="rule_parameter_id" ref="rule_parameter_us_wi_suta_rate"/>
@@ -42,13 +44,14 @@
         </record>
     </data>
 
-    <!-- Table based on https://www.revenue.wi.gov/DOR%20Publications/pb166.pdf page 25. -->
     <record id="rule_parameter_us_wi_sit_tax_rate" model="hr.rule.parameter">
         <field name="name">US WI Wisconsin SIT Tax Rate</field>
         <field name="code">us_wi_sit_tax_rate</field>
         <field name="country_id" ref="base.us"/>
     </record>
     <data noupdate="1">
+        <!-- Table based on https://www.revenue.wi.gov/DOR%20Publications/pb166.pdf page 25. -->
+        <!-- Unchanged in 2021 -->
         <record id="rule_parameter_us_wi_sit_tax_rate_2020" model="hr.rule.parameter.value">
             <field name="parameter_value">{
                 'single':  (
diff --git a/l10n_us_hr_payroll/tests/test_us_wi_wisconsin_payslip_2021.py b/l10n_us_hr_payroll/tests/test_us_wi_wisconsin_payslip_2021.py
new file mode 100755
index 00000000..59a9e814
--- /dev/null
+++ b/l10n_us_hr_payroll/tests/test_us_wi_wisconsin_payslip_2021.py
@@ -0,0 +1,39 @@
+# Part of Hibou Suite Professional. See LICENSE_PROFESSIONAL file for full copyright and licensing details.
+
+from datetime import date, timedelta
+from .common import TestUsPayslip
+
+
+class TestUsWIPayslip(TestUsPayslip):
+    ###
+    #   2021 Taxes and Rates
+    ###
+    WI_UNEMP_MAX_WAGE = 14000.0
+    WI_UNEMP = 3.05
+    # Calculation based on example https://www.revenue.wi.gov/DOR%20Publications/pb166.pdf
+
+    def _test_sit(self, wage, filing_status, exemption, additional_withholding, exempt, schedule_pay,  date_start, expected_withholding):
+        employee = self._createEmployee()
+        contract = self._createContract(employee,
+                                        wage=wage,
+                                        state_id=self.get_us_state('WI'),
+                                        wi_wt4_sit_filing_status=filing_status,
+                                        wi_wt4_sit_exemptions=exemption,
+                                        state_income_tax_additional_withholding=additional_withholding,
+                                        state_income_tax_exempt=exempt,
+                                        schedule_pay=schedule_pay)
+        payslip = self._createPayslip(employee, date_start, date_start + timedelta(days=7))
+        payslip.compute_sheet()
+        cats = self._getCategories(payslip)
+
+        self._log('Computed period tax: ' + str(expected_withholding))
+        self.assertPayrollAlmostEqual(cats.get('EE_US_SIT', 0.0), -expected_withholding)
+
+    def test_2021_taxes_example(self):
+        self._test_er_suta('WI', self.WI_UNEMP, date(2021, 1, 1), wage_base=self.WI_UNEMP_MAX_WAGE)
+        self._test_sit(300, 'single', 1, 0, False, 'weekly', date(2021, 1, 1), 7.21)
+        self._test_sit(700, 'married', 3, 0, False, 'bi-weekly', date(2021, 1, 1), 13.35)
+        self._test_sit(7000, 'single', 1, 10, True, 'bi-weekly', date(2021, 1, 1), 0.00)
+        self._test_sit(10000, 'married', 3, 10, False, 'bi-weekly', date(2021, 1, 1), 633.65)
+        # ((48000 - 26227) * (7.0224 /100) + 1073.55 - 44) / 12
+        self._test_sit(4000, 'single', 2, 0, False, 'monthly', date(2021, 1, 1), 213.21)