diff --git a/.changeset/strange-vans-sit.md b/.changeset/strange-vans-sit.md
new file mode 100644
index 00000000..483011fe
--- /dev/null
+++ b/.changeset/strange-vans-sit.md
@@ -0,0 +1,5 @@
+---
+"permissionless": patch
+---
+
+Added encodeNonce util function
diff --git a/packages/permissionless/utils/encodeNonce.test.ts b/packages/permissionless/utils/encodeNonce.test.ts
new file mode 100644
index 00000000..f3214f2e
--- /dev/null
+++ b/packages/permissionless/utils/encodeNonce.test.ts
@@ -0,0 +1,38 @@
+import { encodeNonce } from "permissionless/utils"
+import { toHex } from "viem"
+import { describe, expect, test } from "vitest"
+
+describe("encodeNonce", () => {
+    test("should encode key and sequence correctly", async () => {
+        const key = 123456789012345678901234n
+        const sequence = 9876543210n
+        const expectedKey = BigInt(toHex(key, { size: 24 }))
+        const expectedSequence = BigInt(toHex(sequence, { size: 8 }))
+
+        const result = encodeNonce({ key, sequence })
+
+        expect(result).toBe((expectedKey << BigInt(64)) + expectedSequence)
+    })
+
+    test("should handle zero values correctly", () => {
+        const key = BigInt(0)
+        const sequence = BigInt(0)
+        const expectedKey = BigInt(toHex(key, { size: 24 }))
+        const expectedSequence = BigInt(toHex(sequence, { size: 8 }))
+
+        const result = encodeNonce({ key, sequence })
+
+        expect(result).toBe((expectedKey << BigInt(64)) + expectedSequence)
+    })
+
+    test("should handle large values correctly", () => {
+        const key = BigInt("0xFFFFFFFFFFFFFFFFFFFFFFFF")
+        const sequence = BigInt("0xFFFFFFFF")
+        const expectedKey = BigInt(toHex(key, { size: 24 }))
+        const expectedSequence = BigInt(toHex(sequence, { size: 8 }))
+
+        const result = encodeNonce({ key, sequence })
+
+        expect(result).toBe((expectedKey << BigInt(64)) + expectedSequence)
+    })
+})
diff --git a/packages/permissionless/utils/encodeNonce.ts b/packages/permissionless/utils/encodeNonce.ts
new file mode 100644
index 00000000..89387fa5
--- /dev/null
+++ b/packages/permissionless/utils/encodeNonce.ts
@@ -0,0 +1,8 @@
+import { toHex } from "viem"
+
+export function encodeNonce(args: { key: bigint; sequence: bigint }): bigint {
+    const key = BigInt(toHex(args.key, { size: 24 }))
+    const sequence = BigInt(toHex(args.sequence, { size: 8 }))
+
+    return (key << BigInt(64)) + sequence
+}
diff --git a/packages/permissionless/utils/index.ts b/packages/permissionless/utils/index.ts
index 99d5896c..ef3fee6a 100644
--- a/packages/permissionless/utils/index.ts
+++ b/packages/permissionless/utils/index.ts
@@ -23,6 +23,7 @@ export function parseAccount(account: Address | Account): Account {
         return { address: account, type: "json-rpc" }
     return account
 }
+import { encodeNonce } from "./encodeNonce"
 import {
     ENTRYPOINT_ADDRESS_V06,
     ENTRYPOINT_ADDRESS_V07,
@@ -47,6 +48,7 @@ export {
     getAddressFromInitCodeOrPaymasterAndData,
     getPackedUserOperation,
     getEntryPointVersion,
+    encodeNonce,
     ENTRYPOINT_ADDRESS_V06,
     ENTRYPOINT_ADDRESS_V07
 }