diff --git a/src/Core/Wallet/CoinAmount.cs b/src/Core/Wallet/CoinAmount.cs
index 598da2d..8f98d3a 100644
--- a/src/Core/Wallet/CoinAmount.cs
+++ b/src/Core/Wallet/CoinAmount.cs
@@ -46,7 +46,10 @@ public static class CoinAmount
             return false;
         try
         {
-            sats = (long)(value * factor);
+            var satsDecimal = value * factor;
+            if (satsDecimal % 1 != 0)
+                return false;
+            sats = (long)satsDecimal;
         }
         catch (OverflowException)
         {
@@ -65,7 +68,10 @@ public static class CoinAmount
             return false;
         try
         {
-            sats = (long)(coins * SatsPerCoin);
+            var satsDecimal = coins * SatsPerCoin;
+            if (satsDecimal % 1 != 0)
+                return false;
+            sats = (long)satsDecimal;
         }
         catch (OverflowException)
         {
diff --git a/tests/PalladiumWallet.Tests/Wallet/CoinAmountTests.cs b/tests/PalladiumWallet.Tests/Wallet/CoinAmountTests.cs
new file mode 100644
index 0000000..b7b84f7
--- /dev/null
+++ b/tests/PalladiumWallet.Tests/Wallet/CoinAmountTests.cs
@@ -0,0 +1,56 @@
+using PalladiumWallet.Core.Wallet;
+
+namespace PalladiumWallet.Tests.Wallet;
+
+public class CoinAmountTests
+{
+    // --- importi validi ---
+
+    [Theory]
+    [InlineData("1", "sat", 1)]
+    [InlineData("0", "sat", 0)]
+    [InlineData("1.5", "PLM", 150_000_000)]
+    [InlineData("0.00000001", "PLM", 1)]
+    [InlineData("1", "PLM", 100_000_000)]
+    [InlineData("1.00000", "mPLM", 100_000)]
+    [InlineData("1.00", "µPLM", 100)]
+    public void Importo_valido_viene_accettato(string input, string unit, long expectedSats)
+    {
+        Assert.True(CoinAmount.TryParseIn(input, unit, out var sats));
+        Assert.Equal(expectedSats, sats);
+    }
+
+    // --- importi con troppi decimali: devono essere rifiutati ---
+
+    [Theory]
+    [InlineData("1.9", "sat")]          // sat non è divisibile
+    [InlineData("0.001", "µPLM")]       // 0.001 × 100 = 0.1 sat
+    [InlineData("1.500000001", "PLM")]  // 9 decimali, uno di troppo
+    [InlineData("0.000000001", "PLM")]  // sotto al satoshi
+    [InlineData("1.1", "sat")]
+    public void Importo_con_troppi_decimali_viene_rifiutato(string input, string unit)
+    {
+        Assert.False(CoinAmount.TryParseIn(input, unit, out _));
+    }
+
+    // --- TryParseCoins ---
+
+    [Fact]
+    public void TryParseCoins_accetta_precisione_massima()
+    {
+        Assert.True(CoinAmount.TryParseCoins("0.00000001", out var sats));
+        Assert.Equal(1L, sats);
+    }
+
+    [Fact]
+    public void TryParseCoins_rifiuta_sotto_al_satoshi()
+    {
+        Assert.False(CoinAmount.TryParseCoins("0.000000001", out _));
+    }
+
+    [Fact]
+    public void TryParseCoins_rifiuta_importo_negativo()
+    {
+        Assert.False(CoinAmount.TryParseCoins("-1", out _));
+    }
+}