--- a/tests/package.json
+++ b/tests/package.json
@@ -70,7 +70,7 @@
     "testBurnItem": "mocha --timeout 9999999 -r ts-node/register ./**/burnItem.test.ts",
     "testAdminTransferAndBurn": "mocha --timeout 9999999 -r ts-node/register ./**/adminTransferAndBurn.test.ts",
     "testSetPermissions": "mocha --timeout 9999999 -r ts-node/register ./**/setPermissions.test.ts",
-    "testCreditFeesToTreasury": "mocha --timeout 9999999 -r ts-node/register ./**/creditFeesToTreasury.test.ts",
+    "testCreditFeesToTreasury": "mocha --timeout 9999999 -r ts-node/register ./**/creditFeesToTreasury.seqtest.ts",
     "testContractSponsoring": "mocha --timeout 9999999 -r ts-node/register ./**/eth/contractSponsoring.test.ts",
     "testEnableContractSponsoring": "mocha --timeout 9999999 -r ts-node/register ./**/enableContractSponsoring.test.ts",
     "testRemoveFromContractAllowList": "mocha --timeout 9999999 -r ts-node/register ./**/removeFromContractAllowList.test.ts",
@@ -78,8 +78,9 @@
     "testSetOffchainSchema": "mocha --timeout 9999999 -r ts-node/register ./**/setOffchainSchema.test.ts",
     "testNextSponsoring": "mocha --timeout 9999999 -r ts-node/register ./**/nextSponsoring.test.ts",
     "testOverflow": "mocha --timeout 9999999 -r ts-node/register ./**/overflow.test.ts",
-    "testInflation": "mocha --timeout 9999999 -r ts-node/register ./**/inflation.test.ts",
-    "testScheduler": "mocha --timeout 9999999 -r ts-node/register ./**/scheduler.test.ts",
+    "testMaintenance": "mocha --timeout 9999999 -r ts-node/register ./**/maintenanceMode.seqtest.ts",
+    "testInflation": "mocha --timeout 9999999 -r ts-node/register ./**/inflation.seqtest.ts",
+    "testScheduler": "mocha --timeout 9999999 -r ts-node/register ./**/scheduler.seqtest.ts",
     "testSchedulingEVM": "mocha --timeout 9999999 -r ts-node/register ./**/eth/scheduling.test.ts",
     "testPalletPresence": "mocha --timeout 9999999 -r ts-node/register ./**/pallet-presence.test.ts",
     "testBlockProduction": "mocha --timeout 9999999 -r ts-node/register ./**/block-production.test.ts",
@@ -93,7 +94,7 @@
     "testFT": "mocha --timeout 9999999 -r ts-node/register ./**/fungible.test.ts",
     "testEthFT": "mocha --timeout 9999999 -r ts-node/register ./**/eth/fungible.test.ts",
     "testRPC": "mocha --timeout 9999999 -r ts-node/register ./**/rpc.test.ts",
-    "testPromotion": "yarn setup && mocha --timeout 9999999 -r ts-node/register ./**/app-promotion.test.ts",
+    "testPromotion": "yarn setup && mocha --timeout 9999999 -r ts-node/register ./**/app-promotion.*test.ts",
     "testXcmUnique": "RUN_XCM_TESTS=1 mocha --timeout 9999999 -r ts-node/register ./**/xcm/xcmUnique.test.ts",
     "testXcmQuartz": "RUN_XCM_TESTS=1 mocha --timeout 9999999 -r ts-node/register ./**/xcm/xcmQuartz.test.ts",
     "testXcmOpal": "RUN_XCM_TESTS=1 mocha --timeout 9999999 -r ts-node/register ./**/xcm/xcmOpal.test.ts",
--- /dev/null
+++ b/tests/src/maintenanceMode.seqtest.ts
@@ -0,0 +1,264 @@
+// Copyright 2019-2022 Unique Network (Gibraltar) Ltd.
+// This file is part of Unique Network.
+
+// Unique Network is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Unique Network is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Unique Network. If not, see <http://www.gnu.org/licenses/>.
+
+import {IKeyringPair} from '@polkadot/types/types';
+import {ApiPromise} from '@polkadot/api';
+import {expect, itSub, Pallets, usingPlaygrounds} from './util';
+import {itEth} from './eth/util';
+
+async function maintenanceEnabled(api: ApiPromise): Promise<boolean> {
+  return (await api.query.maintenance.enabled()).toJSON() as boolean;
+}
+
+describe('Integration Test: Maintenance Mode', () => {
+  let superuser: IKeyringPair;
+  let donor: IKeyringPair;
+  let bob: IKeyringPair;
+
+  before(async () => {
+    await usingPlaygrounds(async (helper, privateKey) => {
+      superuser = await privateKey('//Alice');
+      donor = await privateKey({filename: __filename});
+      [bob] = await helper.arrange.createAccounts([100n], donor);
+
+      if (await maintenanceEnabled(helper.getApi())) {
+        console.warn('\tMaintenance mode was left enabled BEFORE the test suite! Disabling it now.');
+        await expect(helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.disable', [])).to.be.fulfilled;
+      }
+    });
+  });
+
+  itSub('Allows superuser to enable and disable maintenance mode - and disallows anyone else', async ({helper}) => {
+    // Make sure non-sudo can't enable maintenance mode
+    await expect(helper.executeExtrinsic(superuser, 'api.tx.maintenance.enable', []), 'on commoner enabling MM').to.be.rejected; //With(/NoPermission/);
+
+    // Set maintenance mode
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.enable', []);
+    expect(await maintenanceEnabled(helper.getApi()), 'MM is OFF when it should be ON').to.be.true;
+
+    // Make sure non-sudo can't disable maintenance mode
+    await expect(helper.executeExtrinsic(bob, 'api.tx.maintenance.disable', []), 'on commoner disabling MM').to.be.rejected; //With(/NoPermission/);
+
+    // Disable maintenance mode
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.disable', []);
+    expect(await maintenanceEnabled(helper.getApi()), 'MM is ON when it should be OFF').to.be.false;
+  });
+
+  itSub('MM blocks unique pallet calls', async ({helper}) => {
+    // Can create an NFT collection before enabling the MM
+    const nftCollection = await helper.nft.mintCollection(bob, {
+      tokenPropertyPermissions: [{key: 'test', permission: {
+        collectionAdmin: true,
+        tokenOwner: true,
+        mutable: true,
+      }}],
+    });
+
+    // Can mint an NFT before enabling the MM
+    const nft = await nftCollection.mintToken(bob);
+
+    // Can create an FT collection before enabling the MM
+    const ftCollection = await helper.ft.mintCollection(superuser);
+
+    // Can mint an FT before enabling the MM
+    await expect(ftCollection.mint(superuser)).to.be.fulfilled;
+
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.enable', []);
+    expect(await maintenanceEnabled(helper.getApi()), 'MM is OFF when it should be ON').to.be.true;
+
+    // Unable to create a collection when the MM is enabled
+    await expect(helper.nft.mintCollection(superuser), 'cudo forbidden stuff').to.be.rejected;
+
+    // Unable to set token properties when the MM is enabled
+    await expect(nft.setProperties(
+      bob,
+      [{key: 'test', value: 'test-val'}],
+    )).to.be.rejected;
+
+    // Unable to mint an NFT when the MM is enabled
+    await expect(nftCollection.mintToken(superuser)).to.be.rejected;
+
+    // Unable to mint an FT when the MM is enabled
+    await expect(ftCollection.mint(superuser)).to.be.rejected;
+
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.disable', []);
+    expect(await maintenanceEnabled(helper.getApi()), 'MM is ON when it should be OFF').to.be.false;
+
+    // Can create a collection after disabling the MM
+    await expect(helper.nft.mintCollection(bob), 'MM is disabled, the collection should be created').to.be.fulfilled;
+
+    // Can set token properties after disabling the MM
+    await nft.setProperties(bob, [{key: 'test', value: 'test-val'}]);
+
+    // Can mint an NFT after disabling the MM
+    await nftCollection.mintToken(bob);
+
+    // Can mint an FT after disabling the MM
+    await ftCollection.mint(superuser);
+  });
+
+  itSub.ifWithPallets('MM blocks unique pallet calls (Re-Fungible)', [Pallets.ReFungible], async ({helper}) => {
+    // Can create an RFT collection before enabling the MM
+    const rftCollection = await helper.rft.mintCollection(superuser);
+
+    // Can mint an RFT before enabling the MM
+    await expect(rftCollection.mintToken(superuser)).to.be.fulfilled;
+
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.enable', []);
+    expect(await maintenanceEnabled(helper.getApi()), 'MM is OFF when it should be ON').to.be.true;
+
+    // Unable to mint an RFT when the MM is enabled
+    await expect(rftCollection.mintToken(superuser)).to.be.rejected;
+    
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.disable', []);
+    expect(await maintenanceEnabled(helper.getApi()), 'MM is ON when it should be OFF').to.be.false;
+
+    // Can mint an RFT after disabling the MM
+    await rftCollection.mintToken(superuser);
+  });
+
+  itSub('MM allows native token transfers and RPC calls', async ({helper}) => {
+    // We can use RPC before the MM is enabled
+    const totalCount = await helper.collection.getTotalCount();
+
+    // We can transfer funds before the MM is enabled
+    await expect(helper.balance.transferToSubstrate(superuser, bob.address, 2n)).to.be.fulfilled;
+
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.enable', []);
+    expect(await maintenanceEnabled(helper.getApi()), 'MM is OFF when it should be ON').to.be.true;
+
+    // RPCs work while in maintenance
+    expect(await helper.collection.getTotalCount()).to.be.deep.equal(totalCount);
+
+    // We still able to transfer funds
+    await expect(helper.balance.transferToSubstrate(bob, superuser.address, 1n)).to.be.fulfilled;
+
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.disable', []);
+    expect(await maintenanceEnabled(helper.getApi()), 'MM is ON when it should be OFF').to.be.false;
+
+    // RPCs work after maintenance
+    expect(await helper.collection.getTotalCount()).to.be.deep.equal(totalCount);
+
+    // Transfers work after maintenance
+    await expect(helper.balance.transferToSubstrate(bob, superuser.address, 1n)).to.be.fulfilled;
+  });
+
+  itSub.ifWithPallets('MM blocks scheduled calls and the scheduler itself', [Pallets.Scheduler], async ({helper}) => {
+    const collection = await helper.nft.mintCollection(bob);
+
+    const nftBeforeMM = await collection.mintToken(bob);
+    const nftDuringMM = await collection.mintToken(bob);
+    const nftAfterMM = await collection.mintToken(bob);
+
+    const scheduledIdBeforeMM = '0x' + '0'.repeat(31) + '0';
+    const scheduledIdDuringMM = '0x' + '0'.repeat(31) + '1';
+    const scheduledIdBunkerThroughMM = '0x' + '0'.repeat(31) + '2';
+    const scheduledIdAttemptDuringMM = '0x' + '0'.repeat(31) + '3';
+    const scheduledIdAfterMM = '0x' + '0'.repeat(31) + '4';
+
+    const blocksToWait = 6;
+
+    // Scheduling works before the maintenance
+    await nftBeforeMM.scheduleAfter(scheduledIdBeforeMM, blocksToWait)
+      .transfer(bob, {Substrate: superuser.address});
+
+    await helper.wait.newBlocks(blocksToWait + 1);
+    expect(await nftBeforeMM.getOwner()).to.be.deep.equal({Substrate: superuser.address});
+
+    // Schedule a transaction that should occur *during* the maintenance
+    await nftDuringMM.scheduleAfter(scheduledIdDuringMM, blocksToWait)
+      .transfer(bob, {Substrate: superuser.address});
+    
+    // Schedule a transaction that should occur *after* the maintenance
+    await nftDuringMM.scheduleAfter(scheduledIdBunkerThroughMM, blocksToWait * 2)
+      .transfer(bob, {Substrate: superuser.address});
+
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.enable', []);
+    expect(await maintenanceEnabled(helper.getApi()), 'MM is OFF when it should be ON').to.be.true;
+
+    await helper.wait.newBlocks(blocksToWait + 1);
+    // The owner should NOT change since the scheduled transaction should be rejected
+    expect(await nftDuringMM.getOwner()).to.be.deep.equal({Substrate: bob.address});
+
+    // Any attempts to schedule a tx during the MM should be rejected
+    await expect(nftDuringMM.scheduleAfter(scheduledIdAttemptDuringMM, blocksToWait)
+      .transfer(bob, {Substrate: superuser.address})).to.be.rejected;
+
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.disable', []);
+    expect(await maintenanceEnabled(helper.getApi()), 'MM is ON when it should be OFF').to.be.false;
+
+    // Scheduling works after the maintenance
+    await nftAfterMM.scheduleAfter(scheduledIdAfterMM, blocksToWait)
+      .transfer(bob, {Substrate: superuser.address});
+    
+    await helper.wait.newBlocks(blocksToWait + 1);
+
+    expect(await nftAfterMM.getOwner()).to.be.deep.equal({Substrate: superuser.address});
+    // The owner of the token scheduled for transaction *before* maintenance should now change *after* maintenance
+    expect(await nftDuringMM.getOwner()).to.be.deep.equal({Substrate: superuser.address});
+  });
+
+  itEth('Disallows Ethereum transactions to execute while in maintenance', async ({helper}) => {
+    const owner = await helper.eth.createAccountWithBalance(donor);
+    const receiver = helper.eth.createAccount();
+    
+    const {collectionAddress} = await helper.eth.createERC721MetadataCompatibleNFTCollection(owner, 'A', 'B', 'C', '');
+
+    // Set maintenance mode
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.enable', []);
+    expect(await maintenanceEnabled(helper.getApi()), 'MM is OFF when it should be ON').to.be.true;
+
+    const contract = helper.ethNativeContract.collection(collectionAddress, 'nft', owner);
+    const tokenId = await contract.methods.nextTokenId().call();
+    expect(tokenId).to.be.equal('1');
+
+    /*const result = */
+    await contract.methods.mintWithTokenURI(
+      receiver,
+      'Test URI',
+    ).send();
+    /*const expectedTokenId = result.events.Transfer.returnValues.tokenId;
+    expect(expectedTokenId).to.be.equal(tokenId);*/
+
+    await expect(contract.methods.ownerOf(tokenId).call()).rejectedWith(/token not found/);
+
+    // Disable maintenance mode
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.disable', []);
+    expect(await maintenanceEnabled(helper.getApi()), 'MM is ON when it should be OFF').to.be.false;
+  });
+
+  itSub('Allows to enable and disable MM repeatedly', async ({helper}) => {
+    // Set maintenance mode
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.enable', []);
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.enable', []);
+    expect(await maintenanceEnabled(helper.getApi()), 'MM is OFF when it should be ON').to.be.true;
+
+    // Disable maintenance mode
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.disable', []);
+    await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.disable', []);
+    expect(await maintenanceEnabled(helper.getApi()), 'MM is ON when it should be OFF').to.be.false;
+  });
+
+  afterEach(async () => {
+    await usingPlaygrounds(async helper => {
+      if (await maintenanceEnabled(helper.getApi())) {
+        console.warn('\tMaintenance mode was left enabled AFTER a test has finished! Be careful. Disabling it now.');
+        await helper.getSudo().executeExtrinsic(superuser, 'api.tx.maintenance.disable', []);
+      }
+      expect(await maintenanceEnabled(helper.getApi()), 'Disastrous! Exited the test suite with maintenance mode on.').to.be.false;
+    });
+  });
+});
\ No newline at end of file
--- a/tests/src/util/playgrounds/unique.dev.ts
+++ b/tests/src/util/playgrounds/unique.dev.ts
@@ -86,6 +86,10 @@
           extrinsic: {},
           payload: {},
         },
+        CheckMaintenance: {
+          extrinsic: {},
+          payload: {},
+        },
         FakeTransactionFinalizer: {
           extrinsic: {},
           payload: {},