diff --git a/x/bank/types/balance.go b/x/bank/types/balance.go
index a84845df4a..a986398449 100644
--- a/x/bank/types/balance.go
+++ b/x/bank/types/balance.go
@@ -3,6 +3,7 @@ package types
 import (
 	"bytes"
 	"encoding/json"
+	"fmt"
 	"sort"
 
 	"cosmossdk.io/x/bank/exported"
@@ -51,7 +52,7 @@ func (b balanceByAddress) Swap(i, j int) {
 	b.balances[i], b.balances[j] = b.balances[j], b.balances[i]
 }
 
-// SanitizeGenesisBalances sorts addresses and coin sets.
+// SanitizeGenesisBalances checks for duplicates and sorts addresses and coin sets.
 func SanitizeGenesisBalances(balances []Balance) []Balance {
 	// Given that this function sorts balances, using the standard library's
 	// Quicksort based algorithms, we have algorithmic complexities of:
@@ -64,12 +65,18 @@ func SanitizeGenesisBalances(balances []Balance) []Balance {
 
 	// 1. Retrieve the address equivalents for each Balance's address.
 	addresses := make([]sdk.AccAddress, len(balances))
+	// 2. Track any duplicate addresses to avoid false positives on invariant checks.
+	seen := make(map[string]struct{})
 	for i := range balances {
 		addr, _ := sdk.AccAddressFromBech32(balances[i].Address)
 		addresses[i] = addr
+		if _, exists := seen[string(addr)]; exists {
+			panic(fmt.Sprintf("genesis state has a duplicate account: %q aka %x", balances[i].Address, addr))
+		}
+		seen[string(addr)] = struct{}{}
 	}
 
-	// 2. Sort balances.
+	// 3. Sort balances.
 	sort.Sort(balanceByAddress{addresses: addresses, balances: balances})
 
 	return balances
diff --git a/x/bank/types/balance_test.go b/x/bank/types/balance_test.go
index 323639341d..2e0d3e7c51 100644
--- a/x/bank/types/balance_test.go
+++ b/x/bank/types/balance_test.go
@@ -1,6 +1,7 @@
 package types_test
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -171,6 +172,44 @@ func TestSanitizeBalances(t *testing.T) {
 	}
 }
 
+func TestSanitizeBalancesDuplicates(t *testing.T) {
+	// 1. Generate balances
+	tokens := sdk.TokensFromConsensusPower(81, sdk.DefaultPowerReduction)
+	coin := sdk.NewCoin("benchcoin", tokens)
+	coins := sdk.Coins{coin}
+	addrs, _ := makeRandomAddressesAndPublicKeys(13)
+
+	var balances []bank.Balance
+	for _, addr := range addrs {
+		balances = append(balances, bank.Balance{
+			Address: addr.String(),
+			Coins:   coins,
+		})
+	}
+
+	// 2. Add duplicate
+	dupIdx := 3
+	balances = append(balances, balances[dupIdx])
+	addr, _ := sdk.AccAddressFromBech32(balances[dupIdx].Address)
+	expectedError := fmt.Sprintf("genesis state has a duplicate account: %q aka %x", balances[dupIdx].Address, addr)
+
+	// 3. Add more balances
+	coin2 := sdk.NewCoin("coinbench", tokens)
+	coins2 := sdk.Coins{coin2, coin}
+	addrs2, _ := makeRandomAddressesAndPublicKeys(31)
+	for _, addr := range addrs2 {
+		balances = append(balances, bank.Balance{
+			Address: addr.String(),
+			Coins:   coins2,
+		})
+	}
+
+	// 4. Execute SanitizeGenesisBalances and expect an error
+	require.PanicsWithValue(t, expectedError, func() {
+		bank.SanitizeGenesisBalances(balances)
+	}, "SanitizeGenesisBalances should panic with duplicate accounts")
+}
+
 func makeRandomAddressesAndPublicKeys(n int) (accL []sdk.AccAddress, pkL []*ed25519.PubKey) {
 	for i := 0; i < n; i++ {
 		pk := ed25519.GenPrivKey().PubKey().(*ed25519.PubKey)