diff --git a/src/commonMain/kotlin/uk/gov/hmrc/calculator/Calculator.kt b/src/commonMain/kotlin/uk/gov/hmrc/calculator/Calculator.kt
index ba049b6..b13c1c2 100644
--- a/src/commonMain/kotlin/uk/gov/hmrc/calculator/Calculator.kt
+++ b/src/commonMain/kotlin/uk/gov/hmrc/calculator/Calculator.kt
@@ -147,14 +147,20 @@ class Calculator(
         return when (taxCode) {
             is StandardTaxCode, is AdjustedTaxFreeTCode, is EmergencyTaxCode, is MarriageTaxCodes ->
                 getTotalFromBands(adjustTaxBands(taxBands, taxCode), yearlyWages)
-            is NoTaxTaxCode -> yearlyWages * taxCode.taxFreeAmount
-            is SingleBandTax -> yearlyWages * taxBands[taxCode.taxAllAtBand].percentageAsDecimal
+            is NoTaxTaxCode -> getTotalFromSingleBand(yearlyWages, taxCode.taxFreeAmount)
+            is SingleBandTax -> getTotalFromSingleBand(yearlyWages, taxBands[taxCode.taxAllAtBand].percentageAsDecimal)
             is KTaxCode ->
                 getTotalFromBands(adjustTaxBands(taxBands, taxCode), yearlyWages + taxCode.amountToAddToWages)
             else -> throw InvalidTaxCodeException("$this is an invalid tax code")
         }
     }
 
+    private fun getTotalFromSingleBand(yearlyWage: Double, percentageForSingleBand: Double): Double {
+        val taxToPayForSingleBand: Double = yearlyWage * percentageForSingleBand
+        bandBreakdown.add(BandBreakdown(percentageForSingleBand, taxToPayForSingleBand))
+        return taxToPayForSingleBand
+    }
+
     private fun adjustTaxBands(taxBands: List<Band>, taxCode: TaxCode): List<Band> {
         // The full tax free amount e.g. 12509
         val bandAdjuster = getDefaultTaxAllowance(taxYear, taxCode.country)
diff --git a/src/commonTest/kotlin/uk/gov/hmrc/calculator/model/CalculatorResponseTests.kt b/src/commonTest/kotlin/uk/gov/hmrc/calculator/model/CalculatorResponseTests.kt
index a16641d..450d64b 100644
--- a/src/commonTest/kotlin/uk/gov/hmrc/calculator/model/CalculatorResponseTests.kt
+++ b/src/commonTest/kotlin/uk/gov/hmrc/calculator/model/CalculatorResponseTests.kt
@@ -45,10 +45,12 @@ class CalculatorResponseTests {
         assertEquals(300.0, response.employersNI)
         assertEquals(300.0, response.totalDeductions)
         assertEquals(700.0, response.takeHome)
-        assertEquals(listOf(
-            BandBreakdown(0.0, 0.0),
-            BandBreakdown(0.2, 2000.0)
-        ), response.taxBreakdown)
+        assertEquals(
+            listOf(
+                BandBreakdown(0.0, 0.0),
+                BandBreakdown(0.2, 2000.0)
+            ), response.taxBreakdown
+        )
         assertEquals(12509.0, response.taxFree)
     }
 
@@ -324,4 +326,37 @@ class CalculatorResponseTests {
             ), response.weekly.taxBreakdown
         )
     }
+
+    @Test
+    fun `SD2`() {
+        val taxCode = "SD2"
+        val wages = 130000.00
+        val response = Calculator(taxCode, wages, payPeriod = YEARLY).run()
+
+        assertEquals(66364.16, response.yearly.totalDeductions)
+        assertEquals(
+            listOf(
+                BandBreakdown(
+                    percentage = 0.46,
+                    amount = 59800.00
+                )
+            ), response.yearly.taxBreakdown
+        )
+    }
+    @Test
+    fun `NT`() {
+        val taxCode = "NT"
+        val wages = 130000.00
+        val response = Calculator(taxCode, wages, payPeriod = YEARLY).run()
+
+        assertEquals(6564.16, response.yearly.totalDeductions)
+        assertEquals(
+            listOf(
+                BandBreakdown(
+                    percentage = 0.00,
+                    amount = 0.00
+                )
+            ), response.yearly.taxBreakdown
+        )
+    }
 }