diff --git a/src/packages/core/api/__mocks__/account.ts b/src/packages/core/api/__mocks__/account.ts
new file mode 100644
index 0000000..991be01
--- /dev/null
+++ b/src/packages/core/api/__mocks__/account.ts
@@ -0,0 +1,7 @@
+export const accountApiInstance = {
+	getBalance: jest.fn()
+}
+
+export const AccountApi = jest.fn().mockImplementation(() => {
+	return accountApiInstance;
+})
\ No newline at end of file
diff --git a/src/packages/core/api/account.ts b/src/packages/core/api/account.ts
new file mode 100644
index 0000000..c620d03
--- /dev/null
+++ b/src/packages/core/api/account.ts
@@ -0,0 +1,31 @@
+import * as config from 'config';
+import { APIServerClass, IAPIConfig } from './APIServer';
+
+export interface ApiBalance {
+	total: number;
+	usable: number;
+	locked: number;
+}
+
+export class AccountApi extends APIServerClass {
+
+	constructor(conf: IAPIConfig = config.nuls.api.explorer) {
+		super({ ...config.nuls.api.explorer, ...conf });
+	}
+
+	async getBalance(address): Promise<ApiBalance> {
+
+		const resource: string = this.getResource('balance', address);
+
+		try {
+			return (await this.api.get(resource)).data;
+
+		} catch (e) {
+
+			throw this.handleErrors(e);
+
+		}
+
+	}
+
+}
diff --git a/src/packages/core/common.ts b/src/packages/core/common.ts
index ef84ec4..e46053e 100644
--- a/src/packages/core/common.ts
+++ b/src/packages/core/common.ts
@@ -1,6 +1,6 @@
 export const HASH_LENGTH = 34;
 export const ADDRESS_LENGTH = 23;
-export const P2SH_ADDRESS_TYPE = 3;
+
 export const CONSENSUS_LOCK_TIME = -1;
 
 export const BLACK_HOLE_ADDRESS = 'Nse5FeeiYk1opxdc5RqYpEWkiUDGNuLs';
diff --git a/src/packages/core/protocol/__tests__/account.spec.ts b/src/packages/core/protocol/__tests__/account.spec.ts
index 5e59658..2886c4a 100644
--- a/src/packages/core/protocol/__tests__/account.spec.ts
+++ b/src/packages/core/protocol/__tests__/account.spec.ts
@@ -1,9 +1,12 @@
 import { Account, AddressType, ChainIdType, CustomAddressPosition } from '../../index';
+//import { accountApiInstance } from '../../api/__mocks__/account';
+import * as accountModule from '../../api/account';
 import { randomBytes } from 'crypto';
 import { publicKeyCreate, verify } from 'secp256k1';
 
 jest.mock('crypto');
 jest.mock('secp256k1');
+jest.mock('../../api/account');
 
 describe('create new accounts', () => {
 
@@ -13,6 +16,40 @@ describe('create new accounts', () => {
  
 	describe('valid private key', () => {
 
+		describe('balance', () => {
+
+			it('getting the balance of an account', async () => {
+
+				// This API (explorer.nuls.services) doesn't currently work for new addresses
+				// If it would, this is what a test could look like:
+
+				// const account = Account.create();
+
+				// account.switchChain(ChainIdType.Testnet);
+				// let balance = await account.getBalance({host: 'https://explorer.nuls.services', base: ''});
+				// console.log(balance);
+
+				// expect(balance).toEqual({
+				// 	total: 0,
+				// 	locked: 0,
+				// 	usable: 0
+				// });
+				// Using a pre-defined address..
+
+				const accountApiInstance = new accountModule.AccountApi();
+				accountApiInstance.getBalance.mockResolvedValueOnce({total: 9999999999999, locked: 0, usable: 9999999999999});
+
+				const address = 'TTatyig2SCtmUEsgguKvxQQ421e6NULS';
+				const balance = await Account.getBalance(address, {host: 'https://explorer.nuls.services', base: ''});
+
+				expect(balance.locked + balance.usable).toEqual(balance.total);
+				expect(balance.total).toEqual(9999999999999);
+				expect(balance.locked).toEqual(0);
+				expect(balance.usable).toEqual(9999999999999);
+
+			});
+		});
+
 		describe('create', () => {
 
 			it('creating a new account', () => {
diff --git a/src/packages/core/protocol/account.ts b/src/packages/core/protocol/account.ts
index 1c16c38..76b9be8 100644
--- a/src/packages/core/protocol/account.ts
+++ b/src/packages/core/protocol/account.ts
@@ -5,7 +5,11 @@ import Hex from 'crypto-js/enc-hex';
 import Base64 from 'crypto-js/enc-base64';
 
 import * as secp256k1 from 'secp256k1';
-import { getPrivateKeyBuffer, getXOR, sha256, ripemd160 } from '../utils';
+import { getPrivateKeyBuffer, getXOR, sha256, ripemd160, isValidAddress } from '../utils';
+
+
+import { IAPIConfig } from '..';
+import { AccountApi, ApiBalance } from '../api/account';
 
 export interface AccountObject {
 	address: string;
@@ -16,7 +20,8 @@ export interface AccountObject {
 
 export enum AddressType {
 	Default = 1,
-	Contract = 2
+	Contract = 2,
+	P2SH	= 3
 }
 
 export enum ChainIdType {
@@ -65,6 +70,21 @@ export class Account {
 	/** Public key HEX Buffer */
 	private publicKeyBuffer: Buffer = Buffer.from([]);
 
+	/* Gets the balance of an address (Testnet only for now) */
+	public static async getBalance(address: string, iapiConfig: IAPIConfig): Promise<ApiBalance> {
+		if(isValidAddress(address)){
+			let accountApi = new AccountApi(iapiConfig);
+			return await accountApi.getBalance(address);
+		} else {
+			throw new Error("Invalid Address Used!");
+		}
+	}
+
+	/* Gets the balance of this account (works for test net only) */
+	public async getBalance(iapiConfig:IAPIConfig): Promise<ApiBalance> {
+		return await Account.getBalance(this.address, iapiConfig);
+	}
+
 	/**
 	 * This will loop around until it finds a matching address
 	 * @param str The string to look for in addresses created - The larger the string the harder it is to find
diff --git a/src/packages/core/utils/__tests__/utils.test.ts b/src/packages/core/utils/__tests__/utils.test.ts
new file mode 100644
index 0000000..1281719
--- /dev/null
+++ b/src/packages/core/utils/__tests__/utils.test.ts
@@ -0,0 +1,26 @@
+import { isValidAddress } from '../crypto';
+
+jest.unmock('crypto');
+jest.unmock('secp256k1');
+
+describe('Address validation checks', () => {
+
+  beforeEach(() => {
+    jest.restoreAllMocks();
+  });
+
+  it('check validity of different addresses', () => {
+
+    expect(isValidAddress("TTavFTDgdQNeYgVQBaNTF6SeK54nswH5")).toEqual(true);
+    expect(isValidAddress("Nsdwnd4auFisFJKU6iDvBxTdPkeg8qkB")).toEqual(true);
+    expect(isValidAddress("Nse3uLgeCBWP48GCGh8L54gnELfpnSG9")).toEqual(true);
+    expect(isValidAddress("NseBuUpi4iwbJsj1UrUb4eiAWav9UY4C")).toEqual(true);
+    expect(isValidAddress("Nse7MZAwVTbdWXxWwgN6vfcPwBYC1izz")).toEqual(true);
+
+
+    expect(isValidAddress("avFTDgdQNeYgVQBaNTF6SeK54nswH5")).toEqual(false);
+    expect(isValidAddress("TTavFTDgdQNeYgVQBaNTF6SeK54nswH5DXXD")).toEqual(false);
+    expect(isValidAddress("")).toEqual(false);
+
+  });
+});
diff --git a/src/packages/core/utils/crypto.ts b/src/packages/core/utils/crypto.ts
index 0a2a3e9..d2c9524 100644
--- a/src/packages/core/utils/crypto.ts
+++ b/src/packages/core/utils/crypto.ts
@@ -2,7 +2,13 @@ import * as bs58 from 'bs58';
 import RIPEMD160 from 'ripemd160';
 import * as secp256k1 from 'secp256k1';
 import * as shajs from 'sha.js';
-import { HASH_LENGTH } from '../common';
+import { 
+  HASH_LENGTH, 
+  ADDRESS_LENGTH,
+  } from '../common';
+
+import { AddressType, ChainIdType } from '../protocol/account';
+
 import { isHex } from './serialize';
 
 export const PRIVATE_KEY_LENGTH = 64;
@@ -53,9 +59,47 @@ export function isValidPrivateKey(privateKey: string): boolean {
 
 }
 
+/*
+https://github.com/nuls-io/nuls/blob/b8e490a26eeec7b16d924d8398a67ede24ff86ca/core-module/kernel/src/main/java/io/nuls/kernel/utils/AddressTool.java#L77-L117
+*/
 export function isValidAddress(address: string): boolean {
 
-  return /^(Ns|TT)([a-zA-Z-0-9]{30})$/.test(address);
+  if(!/^(Ns|TT)([a-zA-Z-0-9]{30})$/.test(address))
+    return false;
+  
+  let bytes: Buffer;
+
+  try {
+    bytes = Buffer.from(bs58.decode(address));
+    if(bytes.length != ADDRESS_LENGTH + 1)
+      return false;
+  } catch {
+    return false;
+  }
+  
+  let chainId: Number;
+  let type: Number;
+
+  try {
+    chainId = bytes.readInt16LE(0);
+    type = bytes.readInt8(2);
+  } catch {
+    return false;
+  }
+
+  if (Object.values(ChainIdType).indexOf(chainId) === -1){
+    return false;
+  }
+  if (Object.values(AddressType).indexOf(type) === -1) {
+    return false;
+  }
+  try {
+    checkXOR(bytes);
+  } catch {
+    return false;
+  } 
+
+  return true;
 
 }
 
@@ -89,6 +133,19 @@ export function getXOR(bytes: Buffer): number {
 
 }
 
+/* 
+https://github.com/nuls-io/nuls/blob/b8e490a26eeec7b16d924d8398a67ede24ff86ca/core-module/kernel/src/main/java/io/nuls/kernel/utils/AddressTool.java#L169-L183
+*/
+export function checkXOR(hashs: Buffer) {
+    
+    const body: Buffer = hashs.slice(0, ADDRESS_LENGTH);
+    const xor = getXOR(body);
+
+    if (xor != hashs[ADDRESS_LENGTH]) {
+        throw new Error("Address XOR doesn't check out.");
+    }
+}
+
 export function addressFromHash(hash: AddressHash): string {
 
   return bs58.encode(Buffer.concat([hash, Buffer.from([getXOR(hash)])]));