diff --git a/lib/check-allowance.js b/lib/check-allowance.js
deleted file mode 100644
index eed255a..0000000
--- a/lib/check-allowance.js
+++ /dev/null
@@ -1,29 +0,0 @@
-const { BigNumber } = require('ethers')
-const { logic } = require('ptokens-utils')
-const { getTokenContract } = require('./get-token-contract')
-
-const TIMEOUT_TIME = 3000
-
-const checkAllowanceIsSufficient = (
-  _amount,
-  _spenderAddress,
-  _ownerAddress,
-  _tokenAddress,
-  _signer,
-) =>
-  console.info(`✔ Checking spender ${_spenderAddress} has sufficient allowance for token ${_tokenAddress}...`) ||
-    logic.racePromise(
-      TIMEOUT_TIME,
-      getTokenContract(_tokenAddress, _signer).allowance,
-      [ _ownerAddress, _spenderAddress ],
-    )
-      .then(_allowance => {
-        if (_allowance.lt(BigNumber.from(_amount))) {
-          return Promise.reject(new Error(`Insufficient allowance to peg in! Got ${_allowance}, need ${_amount}!`))
-        } else {
-          console.info(`✔ Allowance of ${_allowance} is sufficient!`)
-          return
-        }
-      })
-
-module.exports = { checkAllowanceIsSufficient }
diff --git a/lib/check-token-balance.js b/lib/check-token-balance.js
new file mode 100644
index 0000000..7150c3e
--- /dev/null
+++ b/lib/check-token-balance.js
@@ -0,0 +1,24 @@
+const { BigNumber } = require('ethers')
+const { logic } = require('ptokens-utils')
+const { getTokenContract } = require('./get-token-contract')
+const { CONTRACT_CALL_TIME_OUT_TIME } = require('./constants')
+
+const checkTokenBalanceIsSufficient = (_amount, _tokenOwnerAddress, _tokenAddress, _signer) =>
+  console.info(`✔ Checking spender ${_tokenOwnerAddress} has sufficient balance of token ${_tokenAddress}...`) ||
+    logic.racePromise(
+      CONTRACT_CALL_TIME_OUT_TIME,
+      getTokenContract(_tokenAddress, _signer).balanceOf,
+      [ _tokenOwnerAddress ],
+    )
+      .then(_tokenBalance => {
+        if (_tokenBalance.lt(BigNumber.from(_amount))) {
+          return Promise.reject(
+            new Error(`Insufficient token balance to peg in! Got ${_tokenBalance}, need ${_amount}!`)
+          )
+        } else {
+          console.info(`✔ Token balance of ${_tokenBalance} is sufficient!`)
+          return
+        }
+      })
+
+module.exports = { checkTokenBalanceIsSufficient }
diff --git a/lib/check-token-is-supported.js b/lib/check-token-is-supported.js
new file mode 100644
index 0000000..f31d609
--- /dev/null
+++ b/lib/check-token-is-supported.js
@@ -0,0 +1,34 @@
+const { logic } = require('ptokens-utils')
+const { getEthersContract } = require('./utils')
+const { CONTRACT_CALL_TIME_OUT_TIME } = require('./constants')
+
+const VAULT_ABI_FRAGMENT = [{
+  'type': 'function',
+  'stateMutability': 'view',
+  'name': 'isTokenSupported',
+  'outputs': [{ 'internalType': 'bool', 'name': '', 'type': 'bool' }],
+  'inputs': [{ 'internalType': 'address', 'name': '_token', 'type': 'address' }],
+}]
+
+const getVaultContract = (_address, _provider) =>
+  getEthersContract(_address, VAULT_ABI_FRAGMENT, _provider)
+
+const checkTokenIsSupportedInVault = (_vaultAddress, _tokenAddress, _provider) =>
+  console.info(`✔ Checking token @ ${_tokenAddress} is supported in vault @ ${_vaultAddress}...`) ||
+  logic.racePromise(
+    CONTRACT_CALL_TIME_OUT_TIME,
+    getVaultContract(_vaultAddress, _provider).isTokenSupported,
+    [ _tokenAddress ],
+  )
+    .then(_tokenIsSupported => {
+      if (_tokenIsSupported) {
+        console.info('✔ Token is supported in vault contract!')
+        return
+      } else {
+        return Promise.reject(
+          new Error(`Token @ ${_tokenAddress} is NOT supported in vault contract @ ${_vaultAddress}!`)
+        )
+      }
+    })
+
+module.exports = { checkTokenIsSupportedInVault }
diff --git a/lib/constants.js b/lib/constants.js
index 173308a..d462940 100644
--- a/lib/constants.js
+++ b/lib/constants.js
@@ -1,5 +1,6 @@
 module.exports = {
   ENDPOINT_ENV_VAR_KEY: 'ENDPOINT',
+  CONTRACT_CALL_TIME_OUT_TIME: 3000,
   ETHERSCAN_ENV_VAR_KEY: 'ETHERSCAN_API_KEY',
   HARDHAT_CONFIG_FILE_NAME: 'hardhat.config.js',
   FLATTENED_CONTRACT_FILE_NAME: 'flattened.sol',
diff --git a/lib/get-token-contract.js b/lib/get-token-contract.js
index a5a30b5..02f065c 100644
--- a/lib/get-token-contract.js
+++ b/lib/get-token-contract.js
@@ -1,20 +1,37 @@
-/* eslint-disable-next-line no-shadow */
-const ethers = require('ethers')
+const { getEthersContract } = require('./utils')
 
-const TOKEN_ABI = [{
-  'inputs': [
-    { 'internalType': 'address', 'name': 'holder', 'type': 'address' },
-    { 'internalType': 'address', 'name': 'spender', 'type': 'address' }
-  ],
-  'name': 'allowance',
-  'outputs': [ { 'internalType': 'uint256', 'name': '', 'type': 'uint256' } ],
-  'stateMutability': 'view',
-  'type': 'function'
-}]
+const TOKEN_ABI = [
+  {
+    'inputs': [
+      { 'internalType': 'address', 'name': 'holder', 'type': 'address' },
+      { 'internalType': 'address', 'name': 'spender', 'type': 'address' }
+    ],
+    'name': 'allowance',
+    'outputs': [ { 'internalType': 'uint256', 'name': '', 'type': 'uint256' } ],
+    'stateMutability': 'view',
+    'type': 'function'
+  },
+  {
+    'inputs': [ { 'internalType': 'address', 'name': 'tokenHolder', 'type': 'address' } ],
+    'name': 'balanceOf',
+    'outputs': [ { 'internalType': 'uint256', 'name': '', 'type': 'uint256' } ],
+    'stateMutability': 'view',
+    'type': 'function'
+  },
+  {
+    'inputs': [
+      { 'internalType': 'address', 'name': 'spender', 'type': 'address' },
+      { 'internalType': 'uint256', 'name': 'value', 'type': 'uint256' }
+    ],
+    'name': 'approve',
+    'outputs': [ { 'internalType': 'bool', 'name': '', 'type': 'bool' } ],
+    'stateMutability': 'nonpayable',
+    'type': 'function'
+  },
+]
 
-const getTokenContract = (_address, _signer) => {
-  console.info(`✔ Getting token contract @ '${_address}'...`)
-  return new ethers.Contract(_address, TOKEN_ABI, _signer)
-}
+const getTokenContract = (_address, _signer) =>
+  console.info(`✔ Getting token contract @ '${_address}'...`) ||
+  getEthersContract(_address, TOKEN_ABI, _signer)
 
 module.exports = { getTokenContract }
diff --git a/lib/get-vault-contract.js b/lib/get-vault-contract.js
index 79d7946..df036c4 100644
--- a/lib/get-vault-contract.js
+++ b/lib/get-vault-contract.js
@@ -1,18 +1,17 @@
-/* eslint-disable-next-line no-shadow */
-const ethers = require('ethers')
 const { curry } = require('ramda')
+const { getEthersContract } = require('./utils')
 const { getProvider } = require('./get-provider')
 const { checkEndpoint } = require('./check-endpoint')
-const { getVaultAbi } = require('./get-contract-artifacts')
 const { ENDPOINT_ENV_VAR_KEY } = require('./constants')
 const { getEthersWallet } = require('./get-ethers-wallet')
+const { getVaultAbi } = require('./get-contract-artifacts')
 const { getEnvConfiguration } = require('./get-env-configuration')
 const { getEnvironmentVariable } = require('./get-environment-variable')
 
-const getEthersContract = curry((_address, _abi, _signer) => {
-  console.info(`✔ Getting contract @ '${_address}'...`)
-  return Promise.resolve(new ethers.Contract(_address, _abi, _signer))
-})
+const getVaultEthersContract = curry((_address, _signer) =>
+  console.info('✔ Getting vault contract...') ||
+  getVaultAbi().then(_abi => getEthersContract(_address, _abi, _signer))
+)
 
 const getVaultContract = _deployedContractAddress =>
   console.info(`✔ Getting pToken contract @ '${_deployedContractAddress}'...`) ||
@@ -20,8 +19,8 @@ const getVaultContract = _deployedContractAddress =>
     .then(() => getEnvironmentVariable(ENDPOINT_ENV_VAR_KEY))
     .then(getProvider)
     .then(checkEndpoint)
-    .then(_endpoint => Promise.all([ getEthersWallet(_endpoint), getVaultAbi() ]))
-    .then(([ _wallet, _abi ]) => getEthersContract(_deployedContractAddress, _abi, _wallet))
-    .then(_contract => console.info('✔ Contract retrieved!') || _contract)
+    .then(getEthersWallet)
+    .then(getVaultEthersContract(_deployedContractAddress))
+    .then(_contract => console.info('✔ Vault contract retrieved!') || _contract)
 
 module.exports = { getVaultContract }
diff --git a/lib/maybe-approve-allowance.js b/lib/maybe-approve-allowance.js
new file mode 100644
index 0000000..1cee77d
--- /dev/null
+++ b/lib/maybe-approve-allowance.js
@@ -0,0 +1,33 @@
+const { BigNumber } = require('ethers')
+const { logic } = require('ptokens-utils')
+const { getTokenContract } = require('./get-token-contract')
+const { CONTRACT_CALL_TIME_OUT_TIME } = require('./constants')
+
+const approveAllowance = (_amount, _vaultAddress, _tokenAddress, _signer) =>
+  console.info(`✔ Approving vault to spend ${_amount} tokens, please wait for mining...`) ||
+  getTokenContract(_tokenAddress, _signer)
+    .approve(_vaultAddress, _amount)
+    .then(_tx => _tx.wait())
+    .then(_ => console.info('✔ Approval succeeded! Continuing with peg in...'))
+
+const maybeApproveAllowance = (_amount, _vaultAddress, _ownerAddress, _tokenAddress, _signer) =>
+  console.info(`✔ Checking spender ${_vaultAddress} has sufficient allowance for token ${_tokenAddress}...`) ||
+    logic.racePromise(
+      CONTRACT_CALL_TIME_OUT_TIME,
+      getTokenContract(_tokenAddress, _signer).allowance,
+      [ _ownerAddress, _vaultAddress ],
+    )
+      .then(_allowance => {
+        if (_allowance.lt(BigNumber.from(_amount))) {
+          // NOTE: At least one of the tokens we bridge has a special approval mechanism whereby if we
+          // want to change an allowance that is already > 0, we must first set it to 0 and then to our
+          // desired amount. This logic does NOT currently handle this case.
+          console.info('✘ Allowance is not sufficient!')
+          return approveAllowance(_amount, _vaultAddress, _tokenAddress, _signer)
+        } else {
+          console.info(`✔ Allowance of ${_allowance} is already sufficient!`)
+          return
+        }
+      })
+
+module.exports = { maybeApproveAllowance }
diff --git a/lib/peg-in.js b/lib/peg-in.js
index 97aba67..11dae63 100644
--- a/lib/peg-in.js
+++ b/lib/peg-in.js
@@ -1,9 +1,11 @@
 const { getVaultContract } = require('./get-vault-contract')
-const { checkAllowanceIsSufficient } = require('./check-allowance')
+const { maybeApproveAllowance } = require('./maybe-approve-allowance')
 const { callFxnInContractAndAwaitReceipt } = require('./contract-utils')
+const { checkTokenBalanceIsSufficient } = require('./check-token-balance')
+const { checkTokenIsSupportedInVault } = require('./check-token-is-supported')
 
 const pegIn = (
-  _deployedContractAddress,
+  _vaultAddress,
   _amount,
   _tokenAddress,
   _destinationAddress,
@@ -11,18 +13,26 @@ const pegIn = (
   _userData = '0x',
 ) =>
   console.info('✔ Pegging in...') ||
-  getVaultContract(_deployedContractAddress)
-    .then(_vaultContact => Promise.all([ _vaultContact, _vaultContact.signer.getAddress() ]))
-    .then(([ _vaultContract, _ownerAddress ]) =>
+  getVaultContract(_vaultAddress)
+    .then(_vaultContract => Promise.all([ _vaultContract, _vaultContract.signer.getAddress() ]))
+    .then(([ _vaultContract, _tokenOwnerAddress ]) =>
       Promise.all([
         _vaultContract,
-        checkAllowanceIsSufficient(
-          _amount,
-          _deployedContractAddress, // NOTE: This is the "spender" address, the vault in this case!
-          _ownerAddress,
-          _tokenAddress,
-          _vaultContract.provider,
-        )
+        _tokenOwnerAddress,
+        checkTokenIsSupportedInVault(_vaultAddress, _tokenAddress, _vaultContract.provider),
+      ])
+    )
+    .then(([ _vaultContract, _tokenOwnerAddress, ]) =>
+      Promise.all([
+        _vaultContract,
+        _tokenOwnerAddress,
+        checkTokenBalanceIsSufficient(_amount, _tokenOwnerAddress, _tokenAddress, _vaultContract.provider)
+      ])
+    )
+    .then(([ _vaultContract, _tokenOwnerAddress ]) =>
+      Promise.all([
+        _vaultContract,
+        maybeApproveAllowance(_amount, _vaultAddress, _tokenOwnerAddress, _tokenAddress, _vaultContract.signer)
       ])
     )
     .then(([ _vaultContract ]) =>
diff --git a/lib/utils.js b/lib/utils.js
index 4451d7f..97635f4 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -1,6 +1,7 @@
 const {
   has,
   prop,
+  curry,
 } = require('ramda')
 /* eslint-disable-next-line no-shadow */
 const ethers = require('ethers')
@@ -46,11 +47,17 @@ const maybeHandleEtherscanTrimErrMsg = _err =>
     ))
     : Promise.reject(_err)
 
+const getEthersContract = curry((_address, _abi, _signer) => {
+  console.info(`✔ Getting contract @ '${_address}'...`)
+  return new ethers.Contract(_address, _abi, _signer)
+})
+
 module.exports = {
   maybeHandleEtherscanTrimErrMsg,
   maybeStripHexPrefix,
   maybeAddHexPrefix,
   shortenEthAddress,
+  getEthersContract,
   checkEthAddress,
   getKeyFromObj,
   checkIsHex,
diff --git a/package.json b/package.json
index fa5188a..8b5eef5 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ptokens-erc20-vault-smart-contract",
-  "version": "2.5.0",
+  "version": "2.6.0",
   "description": "The pToken ERC20 vault smart-contract & CLI",
   "main": "cli.js",
   "scripts": {