diff --git a/tests/unit/getAccounts.js b/tests/unit/getAccounts.js
new file mode 100644
index 00000000..1b5bda78
--- /dev/null
+++ b/tests/unit/getAccounts.js
@@ -0,0 +1,100 @@
+/* eslint-disable operator-linebreak */
+'use strict'; // eslint-disable-line
+
+const assert = require('assert');
+const IAMClient = require('../../lib/IAMClient');
+
+const accountIds = ['accountId1', 'accountId2'];
+const canonicalIds = ['canId1', 'canId2'];
+const emailAddresses = ['email1', 'email2'];
+const accountNames = ['name1', 'name2'];
+const opt = { reqUid: 'test.getAccounts.reqUid' };
+const mockCB = () => {};
+
+const expectedData = {
+    Action: 'GetAccounts',
+    Version: '2010-05-08',
+};
+
+describe('getAccounts', () => {
+    let client;
+    let spyArg = null;
+
+    beforeEach('spy on request', done => {
+        client = new IAMClient('127.0.0.1', 8500);
+        client.request = function spy(...args) {
+            spyArg = args;
+        };
+        done();
+    });
+
+    afterEach('reset spyArg', () => { spyArg = null; });
+
+    describe('should send request with regular function signature (5 args)', () => {
+        [
+            { name: 'accountIds', args: [accountIds, null, null, opt, mockCB] },
+            { name: 'emailAddresses', args: [null, emailAddresses, null, opt, mockCB] },
+            { name: 'canonicalIds', args: [null, null, canonicalIds, opt, mockCB] },
+        ].forEach(({ name, args }) => it(`for ${name}`, () => {
+            client.getAccounts(...args);
+            const [method, path, auth, cb, data, reqUid, contentType] = spyArg;
+            assert.strictEqual(method, 'GET');
+            assert.strictEqual(path, '/');
+            assert.strictEqual(auth, false);
+            assert.strictEqual(cb, mockCB);
+            assert.strictEqual(reqUid, opt.reqUid);
+            assert.strictEqual(contentType, null);
+            assert.deepStrictEqual(
+                data,
+                Object.assign({}, expectedData, { [name]: args[0] || args[1] || args[2] }),
+            );
+        }));
+    });
+
+    describe('should send request with new function signature (3args)', () => {
+        [
+            { name: 'accountIds', args: [{ accountIds }, opt, mockCB] },
+            { name: 'emailAddresses', args: [{ emailAddresses }, opt, mockCB] },
+            { name: 'canonicalIds', args: [{ canonicalIds }, opt, mockCB] },
+            { name: 'accountNames', args: [{ accountNames }, opt, mockCB] },
+        ].forEach(({ name, args }) => it(`for ${name}`, () => {
+            client.getAccounts(...args);
+            const [method, path, auth, cb, data, reqUid, contentType] = spyArg;
+            assert.strictEqual(method, 'GET');
+            assert.strictEqual(path, '/');
+            assert.strictEqual(auth, false);
+            assert.strictEqual(cb, mockCB);
+            assert.strictEqual(reqUid, opt.reqUid);
+            assert.strictEqual(contentType, null);
+            assert.deepStrictEqual(
+                data,
+                Object.assign({}, expectedData, { [name]: Object.values(args[0])[0] }),
+            );
+        }));
+    });
+
+    describe('should throw with regular function signature (5args)', () => {
+        it('for all values set', () => {
+            assert.throws(() => client.getAccounts(accountIds, emailAddresses, canonicalIds, opt, mockCB),
+                assert.AssertionError);
+        });
+    });
+
+    describe('should throw with new function signature (3args)', () => {
+        it('for all values set', () => {
+            assert.throws(() => client.getAccounts(
+                {
+                    accountIds, emailAddresses, canonicalIds, accountNames,
+                },
+                opt,
+                mockCB,
+            ),
+            assert.AssertionError);
+        });
+
+        it('for wrong argument type', () => {
+            assert.throws(() => client.getAccounts(accountIds, opt, mockCB),
+                assert.AssertionError);
+        });
+    });
+});