diff --git a/contracts/test/utils/TestEncryptedErrors.sol b/contracts/test/utils/TestEncryptedErrors.sol
new file mode 100644
index 0000000..95be14f
--- /dev/null
+++ b/contracts/test/utils/TestEncryptedErrors.sol
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: BSD-3-Clause-Clear
+pragma solidity ^0.8.24;
+
+import "fhevm/lib/TFHE.sol";
+import { EncryptedErrors } from "../../utils/EncryptedErrors.sol";
+import { MockZamaFHEVMConfig } from "fhevm/config/ZamaFHEVMConfig.sol";
+
+contract TestEncryptedErrors is MockZamaFHEVMConfig, EncryptedErrors {
+    constructor(uint8 totalNumberErrorCodes_) EncryptedErrors(totalNumberErrorCodes_) {
+        for (uint8 i; i <= totalNumberErrorCodes_; i++) {
+            /// @dev It is not possible to access the _errorCodeDefinitions since it is private.
+            TFHE.allow(TFHE.asEuint8(i), msg.sender);
+        }
+    }
+
+    function errorChangeIf(
+        einput encryptedCondition,
+        einput encryptedErrorCode,
+        bytes calldata inputProof,
+        uint8 indexCode
+    ) external returns (euint8 newErrorCode) {
+        ebool condition = TFHE.asEbool(encryptedCondition, inputProof);
+        euint8 errorCode = TFHE.asEuint8(encryptedErrorCode, inputProof);
+        newErrorCode = _errorChangeIf(condition, indexCode, errorCode);
+        _errorSave(newErrorCode);
+        TFHE.allow(newErrorCode, msg.sender);
+    }
+
+    function errorChangeIfNot(
+        einput encryptedCondition,
+        einput encryptedErrorCode,
+        bytes calldata inputProof,
+        uint8 indexCode
+    ) external returns (euint8 newErrorCode) {
+        ebool condition = TFHE.asEbool(encryptedCondition, inputProof);
+        euint8 errorCode = TFHE.asEuint8(encryptedErrorCode, inputProof);
+        newErrorCode = _errorChangeIfNot(condition, indexCode, errorCode);
+        _errorSave(newErrorCode);
+        TFHE.allow(newErrorCode, msg.sender);
+    }
+
+    function errorDefineIf(
+        einput encryptedCondition,
+        bytes calldata inputProof,
+        uint8 indexCode
+    ) external returns (euint8 errorCode) {
+        ebool condition = TFHE.asEbool(encryptedCondition, inputProof);
+        errorCode = _errorDefineIf(condition, indexCode);
+        _errorSave(errorCode);
+        TFHE.allow(errorCode, msg.sender);
+    }
+
+    function errorDefineIfNot(
+        einput encryptedCondition,
+        bytes calldata inputProof,
+        uint8 indexCode
+    ) external returns (euint8 errorCode) {
+        ebool condition = TFHE.asEbool(encryptedCondition, inputProof);
+        errorCode = _errorDefineIfNot(condition, indexCode);
+        _errorSave(errorCode);
+        TFHE.allow(errorCode, msg.sender);
+    }
+
+    function errorGetCodeDefinition(uint8 indexCodeDefinition) external view returns (euint8 errorCode) {
+        errorCode = _errorGetCodeDefinition(indexCodeDefinition);
+    }
+
+    function errorGetCodeEmitted(uint256 errorId) external view returns (euint8 errorCode) {
+        errorCode = _errorGetCodeEmitted(errorId);
+    }
+
+    function errorGetCounter() external view returns (uint256 countErrors) {
+        countErrors = _errorGetCounter();
+    }
+
+    function errorGetNumCodesDefined() external view returns (uint8 totalNumberErrorCodes) {
+        totalNumberErrorCodes = _errorGetNumCodesDefined();
+    }
+}
diff --git a/test/utils/EncryptedErrors.fixture.ts b/test/utils/EncryptedErrors.fixture.ts
new file mode 100644
index 0000000..ba8295e
--- /dev/null
+++ b/test/utils/EncryptedErrors.fixture.ts
@@ -0,0 +1,11 @@
+import { ethers } from "hardhat";
+
+import type { TestEncryptedErrors } from "../../types";
+import { Signers } from "../signers";
+
+export async function deployEncryptedErrors(signers: Signers, numberErrors: number): Promise<TestEncryptedErrors> {
+  const contractFactory = await ethers.getContractFactory("TestEncryptedErrors");
+  const contract = await contractFactory.connect(signers.alice).deploy(numberErrors);
+  await contract.waitForDeployment();
+  return contract;
+}
diff --git a/test/utils/EncryptedErrors.test.ts b/test/utils/EncryptedErrors.test.ts
new file mode 100644
index 0000000..d6edea6
--- /dev/null
+++ b/test/utils/EncryptedErrors.test.ts
@@ -0,0 +1,190 @@
+import { expect } from "chai";
+
+import { createInstances } from "../instance";
+import { reencryptEuint8 } from "../reencrypt";
+import { getSigners, initSigners } from "../signers";
+import { deployEncryptedErrors } from "./EncryptedErrors.fixture";
+
+describe("EncryptedErrors", function () {
+  const NO_ERROR_CODE = BigInt(0);
+
+  before(async function () {
+    await initSigners(3);
+    this.signers = await getSigners();
+    this.instances = await createInstances(this.signers);
+  });
+
+  beforeEach(async function () {
+    const contract = await deployEncryptedErrors(this.signers, 3);
+    this.encryptedErrorsAddress = await contract.getAddress();
+    this.encryptedErrors = contract;
+  });
+
+  it("post-deployment", async function () {
+    expect(await this.encryptedErrors.errorGetCounter()).to.be.eq(BigInt("0"));
+    expect(await this.encryptedErrors.errorGetNumCodesDefined()).to.be.eq(BigInt("3"));
+
+    for (let i = 0; i < 3; i++) {
+      const handle = await this.encryptedErrors.errorGetCodeDefinition(i);
+      expect(
+        await reencryptEuint8(this.signers, this.instances, "alice", handle, this.encryptedErrorsAddress),
+      ).to.be.eq(i);
+    }
+  });
+
+  it("errorDefineIf --> true", async function () {
+    // True --> errorId=0 has errorCode=2
+    const condition = true;
+    const targetErrorCode = 2;
+
+    const input = this.instances.alice.createEncryptedInput(this.encryptedErrorsAddress, this.signers.alice.address);
+    const encryptedData = await input.addBool(condition).encrypt();
+
+    await this.encryptedErrors
+      .connect(this.signers.alice)
+      .errorDefineIf(encryptedData.handles[0], encryptedData.inputProof, targetErrorCode);
+
+    const handle = await this.encryptedErrors.connect(this.signers.alice).errorGetCodeEmitted(0);
+    expect(await reencryptEuint8(this.signers, this.instances, "alice", handle, this.encryptedErrorsAddress)).to.be.eq(
+      targetErrorCode,
+    );
+    expect(await this.encryptedErrors.errorGetCounter()).to.be.eq(BigInt("1"));
+  });
+
+  it("errorDefineIf --> false", async function () {
+    // False --> errorId=1 has errorCode=0
+    const condition = false;
+    const targetErrorCode = 2;
+
+    const input = this.instances.alice.createEncryptedInput(this.encryptedErrorsAddress, this.signers.alice.address);
+    const encryptedData = await input.addBool(condition).encrypt();
+
+    await this.encryptedErrors
+      .connect(this.signers.alice)
+      .errorDefineIf(encryptedData.handles[0], encryptedData.inputProof, targetErrorCode);
+
+    const handle = await this.encryptedErrors.connect(this.signers.alice).errorGetCodeEmitted(0);
+    expect(await reencryptEuint8(this.signers, this.instances, "alice", handle, this.encryptedErrorsAddress)).to.be.eq(
+      NO_ERROR_CODE,
+    );
+    expect(await this.encryptedErrors.errorGetCounter()).to.be.eq(BigInt("1"));
+  });
+
+  it("errorDefineIfNot --> true", async function () {
+    // True --> errorId=0 has errorCode=0
+    const condition = true;
+    const targetErrorCode = 2;
+
+    const input = this.instances.alice.createEncryptedInput(this.encryptedErrorsAddress, this.signers.alice.address);
+    const encryptedData = await input.addBool(condition).encrypt();
+
+    await this.encryptedErrors
+      .connect(this.signers.alice)
+      .errorDefineIfNot(encryptedData.handles[0], encryptedData.inputProof, targetErrorCode);
+
+    const handle = await this.encryptedErrors.connect(this.signers.alice).errorGetCodeEmitted(0);
+    expect(await reencryptEuint8(this.signers, this.instances, "alice", handle, this.encryptedErrorsAddress)).to.be.eq(
+      NO_ERROR_CODE,
+    );
+    expect(await this.encryptedErrors.errorGetCounter()).to.be.eq(BigInt("1"));
+  });
+
+  it("errorDefineIf --> false", async function () {
+    // False --> errorId=1 has errorCode=2
+    const condition = false;
+    const targetErrorCode = 2;
+
+    const input = this.instances.alice.createEncryptedInput(this.encryptedErrorsAddress, this.signers.alice.address);
+    const encryptedData = await input.addBool(condition).encrypt();
+
+    await this.encryptedErrors
+      .connect(this.signers.alice)
+      .errorDefineIfNot(encryptedData.handles[0], encryptedData.inputProof, targetErrorCode);
+
+    const handle = await this.encryptedErrors.connect(this.signers.alice).errorGetCodeEmitted(0);
+    expect(await reencryptEuint8(this.signers, this.instances, "alice", handle, this.encryptedErrorsAddress)).to.be.eq(
+      targetErrorCode,
+    );
+    expect(await this.encryptedErrors.errorGetCounter()).to.be.eq(BigInt("1"));
+  });
+
+  it("errorChangeIf --> true --> change error code", async function () {
+    // True --> change errorCode
+    const condition = true;
+    const errorCode = 1;
+    const targetErrorCode = 2;
+
+    const input = this.instances.alice.createEncryptedInput(this.encryptedErrorsAddress, this.signers.alice.address);
+    const encryptedData = await input.addBool(condition).add8(errorCode).encrypt();
+
+    await this.encryptedErrors
+      .connect(this.signers.alice)
+      .errorChangeIf(encryptedData.handles[0], encryptedData.handles[1], encryptedData.inputProof, targetErrorCode);
+
+    const handle = await this.encryptedErrors.connect(this.signers.alice).errorGetCodeEmitted(0);
+    expect(await reencryptEuint8(this.signers, this.instances, "alice", handle, this.encryptedErrorsAddress)).to.be.eq(
+      targetErrorCode,
+    );
+    expect(await this.encryptedErrors.errorGetCounter()).to.be.eq(BigInt("1"));
+  });
+
+  it("errorChangeIf --> false --> no change for error code", async function () {
+    // False --> no change in errorCode
+    const condition = false;
+    const errorCode = 1;
+    const targetErrorCode = 2;
+
+    const input = this.instances.alice.createEncryptedInput(this.encryptedErrorsAddress, this.signers.alice.address);
+    const encryptedData = await input.addBool(condition).add8(errorCode).encrypt();
+
+    await this.encryptedErrors
+      .connect(this.signers.alice)
+      .errorChangeIf(encryptedData.handles[0], encryptedData.handles[1], encryptedData.inputProof, targetErrorCode);
+
+    const handle = await this.encryptedErrors.connect(this.signers.alice).errorGetCodeEmitted(0);
+    expect(await reencryptEuint8(this.signers, this.instances, "alice", handle, this.encryptedErrorsAddress)).to.be.eq(
+      errorCode,
+    );
+    expect(await this.encryptedErrors.errorGetCounter()).to.be.eq(BigInt("1"));
+  });
+
+  it("errorChangeIfNot --> true --> no change for error code", async function () {
+    // True --> no change errorCode
+    const condition = true;
+    const errorCode = 1;
+    const targetErrorCode = 2;
+
+    const input = this.instances.alice.createEncryptedInput(this.encryptedErrorsAddress, this.signers.alice.address);
+    const encryptedData = await input.addBool(condition).add8(errorCode).encrypt();
+
+    await this.encryptedErrors
+      .connect(this.signers.alice)
+      .errorChangeIfNot(encryptedData.handles[0], encryptedData.handles[1], encryptedData.inputProof, targetErrorCode);
+
+    const handle = await this.encryptedErrors.connect(this.signers.alice).errorGetCodeEmitted(0);
+    expect(await reencryptEuint8(this.signers, this.instances, "alice", handle, this.encryptedErrorsAddress)).to.be.eq(
+      errorCode,
+    );
+    expect(await this.encryptedErrors.errorGetCounter()).to.be.eq(BigInt("1"));
+  });
+
+  it("errorChangeIfNot --> false --> change error code", async function () {
+    // False --> change in errorCode
+    const condition = false;
+    const errorCode = 1;
+    const targetErrorCode = 2;
+
+    const input = this.instances.alice.createEncryptedInput(this.encryptedErrorsAddress, this.signers.alice.address);
+    const encryptedData = await input.addBool(condition).add8(errorCode).encrypt();
+
+    await this.encryptedErrors
+      .connect(this.signers.alice)
+      .errorChangeIfNot(encryptedData.handles[0], encryptedData.handles[1], encryptedData.inputProof, targetErrorCode);
+
+    const handle = await this.encryptedErrors.connect(this.signers.alice).errorGetCodeEmitted(0);
+    expect(await reencryptEuint8(this.signers, this.instances, "alice", handle, this.encryptedErrorsAddress)).to.be.eq(
+      targetErrorCode,
+    );
+    expect(await this.encryptedErrors.errorGetCounter()).to.be.eq(BigInt("1"));
+  });
+});