diff --git a/l10n_us_hr_payroll/data/state/ms_mississippi.xml b/l10n_us_hr_payroll/data/state/ms_mississippi.xml
index a3868e8d..4c6566b7 100644
--- a/l10n_us_hr_payroll/data/state/ms_mississippi.xml
+++ b/l10n_us_hr_payroll/data/state/ms_mississippi.xml
@@ -7,11 +7,7 @@
         <field name="country_id" ref="base.us"/>
     </record>
     <data noupdate="1">
-        <record id="rule_parameter_us_ms_suta_wage_base_2019" model="hr.rule.parameter.value">
-            <field name="parameter_value">14000.0</field>
-            <field name="rule_parameter_id" ref="rule_parameter_us_ms_suta_wage_base"/>
-            <field name="date_from" eval="datetime(2019, 1, 1).date()"/>
-        </record>
+        <!-- not changed for 2021 https://mdes.ms.gov/employer-faqs/ -->
         <record id="rule_parameter_us_ms_suta_wage_base_2020" model="hr.rule.parameter.value">
             <field name="parameter_value">14000.0</field>
             <field name="rule_parameter_id" ref="rule_parameter_us_ms_suta_wage_base"/>
@@ -26,16 +22,18 @@
         <field name="country_id" ref="base.us"/>
     </record>
     <data noupdate="1">
-        <record id="rule_parameter_us_ms_suta_rate_2019" model="hr.rule.parameter.value">
-            <field name="parameter_value">1.2</field>
-            <field name="rule_parameter_id" ref="rule_parameter_us_ms_suta_rate"/>
-            <field name="date_from" eval="datetime(2019, 1, 1).date()"/>
-        </record>
         <record id="rule_parameter_us_ms_suta_rate_2020" model="hr.rule.parameter.value">
             <field name="parameter_value">1.2</field>
             <field name="rule_parameter_id" ref="rule_parameter_us_ms_suta_rate"/>
             <field name="date_from" eval="datetime(2020, 1, 1).date()"/>
         </record>
+        <!-- 1% for first year of new employers -->
+        <!-- https://mdes.ms.gov/employers/unemployment-tax/reporting-and-filing/unemployment-tax-rates/ -->
+        <record id="rule_parameter_us_ms_suta_rate_2021" model="hr.rule.parameter.value">
+            <field name="parameter_value">1.0</field>
+            <field name="rule_parameter_id" ref="rule_parameter_us_ms_suta_rate"/>
+            <field name="date_from" eval="datetime(2021, 1, 1).date()"/>
+        </record>
     </data>
 
     <record id="rule_parameter_us_ms_sit_rate" model="hr.rule.parameter">
@@ -44,15 +42,6 @@
         <field name="country_id" ref="base.us"/>
     </record>
     <data noupdate="1">
-        <record id="rule_parameter_us_ms_sit_rate_2019" model="hr.rule.parameter.value">
-            <field name="parameter_value">[
-                    (  10000.00,  290.0,  0.05),
-                    (   5000.00,   90.0,  0.04),
-                    (   2000.00,    0.0,  0.03),
-                ]</field>
-            <field name="rule_parameter_id" ref="rule_parameter_us_ms_sit_rate"/>
-            <field name="date_from" eval="datetime(2019, 1, 1).date()"/>
-        </record>
         <!-- https://www.dor.ms.gov/Documents/Computer%20Payroll%20Flowchart.pdf -->
         <!-- Table D. -->
         <record id="rule_parameter_us_ms_sit_rate_2020" model="hr.rule.parameter.value">
@@ -64,6 +53,17 @@
             <field name="rule_parameter_id" ref="rule_parameter_us_ms_sit_rate"/>
             <field name="date_from" eval="datetime(2020, 1, 1).date()"/>
         </record>
+        <!-- https://www.dor.ms.gov/Documents/Computer%20Payroll%20Flowchart%209-9-20.pdf -->
+        <!-- Table D. -->
+        <record id="rule_parameter_us_ms_sit_rate_2021" model="hr.rule.parameter.value">
+            <field name="parameter_value">[
+                    (  10000.00,  230.0,  0.05),
+                    (   5000.00,   30.0,  0.04),
+                    (   3000.00,    0.0,  0.03),
+                ]</field>
+            <field name="rule_parameter_id" ref="rule_parameter_us_ms_sit_rate"/>
+            <field name="date_from" eval="datetime(2021, 1, 1).date()"/>
+        </record>
     </data>
 
     <record id="rule_parameter_us_ms_sit_deduction" model="hr.rule.parameter">
@@ -72,18 +72,9 @@
         <field name="country_id" ref="base.us"/>
     </record>
     <data noupdate="1">
-        <record id="rule_parameter_us_ms_sit_deduction_2019" model="hr.rule.parameter.value">
-            <field name="parameter_value">{
-                'single':             2300.0,
-                'head_of_household':  3400.0,
-                'married_dual':       2300.0,
-                'married':            4600.0,
-            }</field>
-            <field name="rule_parameter_id" ref="rule_parameter_us_ms_sit_deduction"/>
-            <field name="date_from" eval="datetime(2019, 1, 1).date()"/>
-        </record>
         <!-- https://www.dor.ms.gov/Documents/Computer%20Payroll%20Flowchart.pdf -->
         <!-- Table C. -->
+        <!-- Unchanged in 2021 https://www.dor.ms.gov/Documents/Computer%20Payroll%20Flowchart%209-9-20.pdf -->
         <record id="rule_parameter_us_ms_sit_deduction_2020" model="hr.rule.parameter.value">
             <field name="parameter_value">{
                 'single':             2300.0,
diff --git a/l10n_us_hr_payroll/tests/test_us_ms_mississippi_payslip_2019.py b/l10n_us_hr_payroll/tests/test_us_ms_mississippi_payslip_2019.py
deleted file mode 100755
index e7ce35d0..00000000
--- a/l10n_us_hr_payroll/tests/test_us_ms_mississippi_payslip_2019.py
+++ /dev/null
@@ -1,94 +0,0 @@
-# Part of Hibou Suite Professional. See LICENSE_PROFESSIONAL file for full copyright and licensing details.
-
-from .common import TestUsPayslip
-
-
-class TestUsMsPayslip(TestUsPayslip):
-    # Calculations from https://www.dor.ms.gov/Documents/Computer%20Payroll%20Accounting%201-2-19.pdf
-    MS_UNEMP = -1.2 / 100.0
-
-    def test_2019_taxes_one(self):
-        salary = 1250.0
-        ms_89_350_exemption = 11000.0
-
-        employee = self._createEmployee()
-        contract = self._createContract(employee,
-                                        wage=salary,
-                                        state_id=self.get_us_state('MS'),
-                                        ms_89_350_sit_filing_status='head_of_household',
-                                        ms_89_350_sit_exemption_value=ms_89_350_exemption,
-                                        state_income_tax_additional_withholding=0.0,
-                                        schedule_pay='semi-monthly')
-
-        self._log('2019 Mississippi tax single first payslip:')
-        payslip = self._createPayslip(employee, '2019-01-01', '2019-01-31')
-
-        payslip.compute_sheet()
-
-        cats = self._getCategories(payslip)
-
-        self.assertPayrollEqual(cats['ER_US_SUTA'], salary * self.MS_UNEMP)
-
-        STDED = 3400.0  # Head of Household
-        AGP = salary * 24  # Semi-Monthly
-        TI = AGP - (ms_89_350_exemption + STDED)
-        self.assertPayrollEqual(TI, 15600.0)
-        TAX = ((TI - 10000) * 0.05) + 290  # Over 10,000
-        self.assertPayrollEqual(TAX, 570.0)
-
-        ms_withhold = round(TAX / 24)  # Semi-Monthly
-        self.assertPayrollEqual(cats['EE_US_SIT'], -ms_withhold)
-
-    def test_2019_taxes_one_exempt(self):
-        salary = 1250.0
-        ms_89_350_exemption = 11000.0
-
-        employee = self._createEmployee()
-        contract = self._createContract(employee,
-                                        wage=salary,
-                                        state_id=self.get_us_state('MS'),
-                                        ms_89_350_sit_filing_status='',
-                                        ms_89_350_sit_exemption_value=ms_89_350_exemption,
-                                        state_income_tax_additional_withholding=0.0,
-                                        schedule_pay='semi-monthly')
-
-        self._log('2019 Mississippi tax single first payslip:')
-        payslip = self._createPayslip(employee, '2019-01-01', '2019-01-31')
-
-        payslip.compute_sheet()
-
-        cats = self._getCategories(payslip)
-        self.assertPayrollEqual(cats.get('EE_US_SIT', 0.0), 0.0)
-
-    def test_2019_taxes_additional(self):
-        salary = 1250.0
-        ms_89_350_exemption = 11000.0
-        additional = 40.0
-
-        employee = self._createEmployee()
-        contract = self._createContract(employee,
-                                        wage=salary,
-                                        state_id=self.get_us_state('MS'),
-                                        ms_89_350_sit_filing_status='head_of_household',
-                                        ms_89_350_sit_exemption_value=ms_89_350_exemption,
-                                        state_income_tax_additional_withholding=additional,
-                                        schedule_pay='semi-monthly')
-
-        self._log('2019 Mississippi tax single first payslip:')
-        payslip = self._createPayslip(employee, '2019-01-01', '2019-01-31')
-
-        payslip.compute_sheet()
-
-        cats = self._getCategories(payslip)
-
-        self.assertPayrollEqual(cats['ER_US_SUTA'], salary * self.MS_UNEMP)
-
-        STDED = 3400.0  # Head of Household
-        AGP = salary * 24  # Semi-Monthly
-        TI = AGP - (ms_89_350_exemption + STDED)
-        self.assertPayrollEqual(TI, 15600.0)
-        TAX = ((TI - 10000) * 0.05) + 290  # Over 10,000
-        self.assertPayrollEqual(TAX, 570.0)
-
-        ms_withhold = round(TAX / 24)  # Semi-Monthly
-        self.assertPayrollEqual(cats['EE_US_SIT'], -ms_withhold + -additional)
diff --git a/l10n_us_hr_payroll/tests/test_us_ms_mississippi_payslip_2021.py b/l10n_us_hr_payroll/tests/test_us_ms_mississippi_payslip_2021.py
new file mode 100755
index 00000000..d59bded9
--- /dev/null
+++ b/l10n_us_hr_payroll/tests/test_us_ms_mississippi_payslip_2021.py
@@ -0,0 +1,35 @@
+# 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 TestUsMsPayslip(TestUsPayslip):
+    # Calculations from https://www.dor.ms.gov/Documents/Computer%20Payroll%20Flowchart.pdf
+    MS_UNEMP = 1.0
+    MS_UNEMP_MAX_WAGE = 14000.0
+
+    def _test_sit(self, wage, filing_status, additional_withholding, exemption, schedule_pay,  date_start, expected_withholding):
+        employee = self._createEmployee()
+        contract = self._createContract(employee,
+                                        wage=wage,
+                                        state_id=self.get_us_state('MS'),
+                                        ms_89_350_sit_filing_status=filing_status,
+                                        state_income_tax_additional_withholding=additional_withholding,
+                                        ms_89_350_sit_exemption_value=exemption,
+                                        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('MS', self.MS_UNEMP, date(2021, 1, 1), wage_base=self.MS_UNEMP_MAX_WAGE)
+        self._test_sit(1250.0, 'head_of_household', 0.0, 11000, 'semi-monthly', date(2021, 1, 1), 21.00)
+        self._test_sit(500.0, '', 5.0, 0, 'bi-weekly', date(2021, 1, 1), 0.00)
+        self._test_sit(12000.0, 'single', 0.0, 11000, 'monthly', date(2021, 1, 1), 522.00)
+        self._test_sit(2500.0, 'married', 5.0, 500, 'bi-weekly', date(2021, 1, 1), 110.00)
+
+