diff --git a/VatValidation/Countries/NO.cs b/VatValidation/Countries/NO.cs
index cbb1394..fd6e540 100644
--- a/VatValidation/Countries/NO.cs
+++ b/VatValidation/Countries/NO.cs
@@ -14,6 +14,10 @@ namespace VatValidation.Countries;
 /// valid, in: 977 074 010MVA, national: 977 074 010, vat: NO 977 074 010, stripped: 977074010, vatstripped: NO 977 074 010
 /// valid, in: NO 977 074 010MVA, national: 977 074 010, vat: NO 977 074 010, stripped: 977074010, vatstripped: NO 977 074 010
 /// valid, in: NO977074010, national: 977 074 010, vat: NO 977 074 010, stripped: 977074010, vatstripped: NO 977 074 010
+/// valid, in: 310033243, national: 310 033 243, vat: NO 310 033 243, stripped: 310033243, comment: test number from skatteetaten.no
+/// invalid, in: 310033242, national: 310033242, vat: NO 310033242, stripped: 310033242
+/// valid, in: 212409472, national: 212 409 472, vat: NO 212 409 472, stripped: 212409472, comment: test number from skatteetaten.no
+/// invalid, in: 212409471, national: 212409471, vat: NO 212409471, stripped: 212409471
 /// </testcases>
 public class NO : CountryBase
 {
@@ -31,7 +35,9 @@ private NO() { }
 	private static readonly int[] _multipliers = [3, 2, 7, 6, 5, 4, 3, 2, 1];
 
 	// https://vatstack.com/articles/norway-vat-number-validation
-	private static bool ValidFormat(ReadOnlySpan<int> d) => d.Length == 9 && (d[0] == 8 || d[0] == 9);
+	private static bool ValidFormat(ReadOnlySpan<int> d) => d.Length == 9 && (
+		d[0] == 2 || d[0] == 3 ||
+		d[0] == 8 || d[0] == 9);
 	internal static bool Valid(ReadOnlySpan<int> digits) => ValidFormat(digits) && Valid(digits.ToArray());
 	private static bool Valid(int[] digits) =>
 		(11 - digits