diff --git a/npm-shrinkwrap.json b/npm-shrinkwrap.json
index 0f307cd2..d3e28395 100644
--- a/npm-shrinkwrap.json
+++ b/npm-shrinkwrap.json
@@ -9,8 +9,8 @@
       "resolved": "https://registry.npmjs.org/async/-/async-0.9.2.tgz"
     },
     "babel-runtime": {
-      "version": "5.8.24",
-      "resolved": "https://registry.npmjs.org/babel-runtime/-/babel-runtime-5.8.24.tgz",
+      "version": "5.8.25",
+      "resolved": "https://registry.npmjs.org/babel-runtime/-/babel-runtime-5.8.25.tgz",
       "dependencies": {
         "core-js": {
           "version": "1.1.4",
@@ -117,12 +117,12 @@
       "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-2.5.2.tgz"
     },
     "ripple-address-codec": {
-      "version": "1.6.0",
-      "resolved": "https://registry.npmjs.org/ripple-address-codec/-/ripple-address-codec-1.6.0.tgz",
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/ripple-address-codec/-/ripple-address-codec-2.0.1.tgz",
       "dependencies": {
         "x-address-codec": {
-          "version": "0.6.0",
-          "resolved": "https://registry.npmjs.org/x-address-codec/-/x-address-codec-0.6.0.tgz",
+          "version": "0.7.0",
+          "resolved": "https://registry.npmjs.org/x-address-codec/-/x-address-codec-0.7.0.tgz",
           "dependencies": {
             "base-x": {
               "version": "1.0.1",
@@ -149,6 +149,22 @@
               "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.1.tgz"
             }
           }
+        },
+        "ripple-address-codec": {
+          "version": "1.6.0",
+          "resolved": "https://registry.npmjs.org/ripple-address-codec/-/ripple-address-codec-1.6.0.tgz",
+          "dependencies": {
+            "x-address-codec": {
+              "version": "0.6.0",
+              "resolved": "https://registry.npmjs.org/x-address-codec/-/x-address-codec-0.6.0.tgz",
+              "dependencies": {
+                "base-x": {
+                  "version": "1.0.1",
+                  "resolved": "https://registry.npmjs.org/base-x/-/base-x-1.0.1.tgz"
+                }
+              }
+            }
+          }
         }
       }
     },
@@ -168,6 +184,20 @@
       "version": "0.7.2",
       "resolved": "https://registry.npmjs.org/ws/-/ws-0.7.2.tgz",
       "dependencies": {
+        "bufferutil": {
+          "version": "1.1.0",
+          "resolved": "https://registry.npmjs.org/bufferutil/-/bufferutil-1.1.0.tgz",
+          "dependencies": {
+            "bindings": {
+              "version": "1.2.1",
+              "resolved": "https://registry.npmjs.org/bindings/-/bindings-1.2.1.tgz"
+            },
+            "nan": {
+              "version": "1.8.4",
+              "resolved": "https://registry.npmjs.org/nan/-/nan-1.8.4.tgz"
+            }
+          }
+        },
         "options": {
           "version": "0.0.6",
           "resolved": "https://registry.npmjs.org/options/-/options-0.0.6.tgz"
@@ -175,6 +205,20 @@
         "ultron": {
           "version": "1.0.2",
           "resolved": "https://registry.npmjs.org/ultron/-/ultron-1.0.2.tgz"
+        },
+        "utf-8-validate": {
+          "version": "1.1.0",
+          "resolved": "https://registry.npmjs.org/utf-8-validate/-/utf-8-validate-1.1.0.tgz",
+          "dependencies": {
+            "bindings": {
+              "version": "1.2.1",
+              "resolved": "https://registry.npmjs.org/bindings/-/bindings-1.2.1.tgz"
+            },
+            "nan": {
+              "version": "1.8.4",
+              "resolved": "https://registry.npmjs.org/nan/-/nan-1.8.4.tgz"
+            }
+          }
         }
       }
     }
diff --git a/package.json b/package.json
index d422f3cc..d1046bd7 100644
--- a/package.json
+++ b/package.json
@@ -26,7 +26,7 @@
     "is-my-json-valid": "^2.12.2",
     "lodash": "^3.1.0",
     "lru-cache": "~2.5.0",
-    "ripple-address-codec": "^1.6.0",
+    "ripple-address-codec": "^2.0.1",
     "ripple-keypairs": "^0.9.0",
     "ripple-lib-transactionparser": "^0.5.1",
     "ripple-lib-value": "0.1.0",
diff --git a/src/core/account.js b/src/core/account.js
index 3e3267bf..1af60f19 100644
--- a/src/core/account.js
+++ b/src/core/account.js
@@ -17,7 +17,7 @@ const util = require('util');
 const {deriveAddress} = require('ripple-keypairs');
 const {EventEmitter} = require('events');
 const {TransactionManager} = require('./transactionmanager');
-const {UInt160} = require('./uint160');
+const {isValidAddress} = require('ripple-address-codec');
 
 /**
  * @constructor Account
@@ -25,14 +25,13 @@ const {UInt160} = require('./uint160');
  * @param {String} account
  */
 
-function Account(remote, account) {
+function Account(remote, address) {
   EventEmitter.call(this);
 
   const self = this;
 
   this._remote = remote;
-  this._account = UInt160.from_json(account);
-  this._account_id = this._account.to_json();
+  this._address = address;
   this._subs = 0;
 
   // Ledger entry object
@@ -43,7 +42,7 @@ function Account(remote, account) {
     if (_.includes(Account.subscribeEvents, type)) {
       if (!self._subs && self._remote._connected) {
         self._remote.requestSubscribe()
-        .addAccount(self._account_id)
+        .addAccount(self._address)
         .broadcast().request();
       }
       self._subs += 1;
@@ -57,7 +56,7 @@ function Account(remote, account) {
       self._subs -= 1;
       if (!self._subs && self._remote._connected) {
         self._remote.requestUnsubscribe()
-        .addAccount(self._account_id)
+        .addAccount(self._address)
         .broadcast().request();
       }
     }
@@ -66,8 +65,8 @@ function Account(remote, account) {
   this.on('removeListener', listenerRemoved);
 
   function attachAccount(request) {
-    if (self._account.is_valid() && self._subs) {
-      request.addAccount(self._account_id);
+    if (isValidAddress(self._address) && self._subs) {
+      request.addAccount(self._address);
     }
   }
 
@@ -81,7 +80,7 @@ function Account(remote, account) {
     let changed = false;
 
     transaction.mmeta.each(function(an) {
-      const isAccount = an.fields.Account === self._account_id;
+      const isAccount = an.fields.Account === self._address;
       const isAccountRoot = isAccount && (an.entryType === 'AccountRoot');
 
       if (isAccountRoot) {
@@ -111,7 +110,7 @@ util.inherits(Account, EventEmitter);
 Account.subscribeEvents = ['transaction', 'entry'];
 
 Account.prototype.toJson = function() {
-  return this._account.to_json();
+  return this._address;
 };
 
 /**
@@ -121,7 +120,7 @@ Account.prototype.toJson = function() {
  */
 
 Account.prototype.isValid = function() {
-  return this._account.is_valid();
+  return isValidAddress(this._address);
 };
 
 /**
@@ -131,7 +130,7 @@ Account.prototype.isValid = function() {
  */
 
 Account.prototype.getInfo = function(callback) {
-  return this._remote.requestAccountInfo({account: this._account_id}, callback);
+  return this._remote.requestAccountInfo({account: this._address}, callback);
 };
 
 /**
@@ -210,7 +209,7 @@ Account.prototype.lines = function(callback_) {
     }
   }
 
-  this._remote.requestAccountLines({account: this._account_id}, accountLines);
+  this._remote.requestAccountLines({account: this._address}, accountLines);
 
   return this;
 };
@@ -275,7 +274,7 @@ Account.prototype.notifyTx = function(transaction) {
     return;
   }
 
-  const isThisAccount = (account === this._account_id);
+  const isThisAccount = (account === this._address);
 
   this.emit(isThisAccount ? 'transaction-outbound' : 'transaction-inbound',
     transaction);
@@ -331,7 +330,7 @@ Account.prototype.publicKeyIsActive = function(public_key, callback) {
     // Catch the case of unfunded accounts
     if (!account_info_res) {
 
-      if (public_key_as_uint160 === self._account_id) {
+      if (public_key_as_uint160 === self._address) {
         async_callback(null, true);
       } else {
         async_callback(null, false);
@@ -373,20 +372,17 @@ Account.prototype.publicKeyIsActive = function(public_key, callback) {
  *  @returns {RippleAddress} Ripple Address
  */
 Account._publicKeyToAddress = function(public_key) {
-  // Based on functions in /src/js/ripple/keypair.js
-  function hexToUInt160(publicKey) {
-    return deriveAddress(publicKey);
-  }
-
-  if (UInt160.is_valid(public_key)) {
+  if (isValidAddress(public_key)) {
     return public_key;
   } else if (/^[0-9a-fA-F]+$/.test(public_key)) {
-    return hexToUInt160(public_key);
+    return deriveAddress(public_key);
   } else { // eslint-disable-line no-else-return
     throw new Error('Public key is invalid. Must be a UInt160 or a hex string');
   }
 };
 
-exports.Account = Account;
+module.exports = {
+  Account
+};
 
 // vim:sw=2:sts=2:ts=8:et
diff --git a/src/core/amount.js b/src/core/amount.js
index 0a7a1224..f2959d4d 100644
--- a/src/core/amount.js
+++ b/src/core/amount.js
@@ -6,9 +6,10 @@
 const assert = require('assert');
 const extend = require('extend');
 const utils = require('./utils');
-const UInt160 = require('./uint160').UInt160;
 const Currency = require('./currency').Currency;
 const {XRPValue, IOUValue} = require('ripple-lib-value');
+const {isValidAddress} = require('ripple-address-codec');
+const {ACCOUNT_ONE, ACCOUNT_ZERO} = require('./constants');
 
 type Value = XRPValue | IOUValue;
 
@@ -21,7 +22,7 @@ function Amount(value = new XRPValue(NaN)) {
   this._value = value;
   this._is_native = true; // Default to XRP. Only valid if value is not NaN.
   this._currency = new Currency();
-  this._issuer = new UInt160();
+  this._issuer = 'NaN';
 }
 
 /**
@@ -105,7 +106,7 @@ Amount.NaN = function() {
 };
 
 Amount.from_components_unsafe = function(value: Value, currency: Currency,
-  issuer: UInt160, isNative: boolean
+  issuer: string, isNative: boolean
 ) {
   const result = new Amount(value);
   result._is_native = isNative;
@@ -402,7 +403,7 @@ Amount.prototype.equals = function(d, ignore_issuer) {
          && this._is_native === d._is_native
          && this._value.equals(d._value)
          && (this._is_native || (this._currency.equals(d._currency)
-              && (ignore_issuer || this._issuer.equals(d._issuer))));
+              && (ignore_issuer || this._issuer === d._issuer)));
 };
 
 // True if Amounts are valid and both native or non-native.
@@ -428,9 +429,8 @@ Amount.prototype.is_valid = function() {
 };
 
 Amount.prototype.is_valid_full = function() {
-  return this.is_valid()
-  && this._currency.is_valid()
-  && this._issuer.is_valid();
+  return this.is_valid() && this._currency.is_valid()
+    && isValidAddress(this._issuer) && this._issuer !== ACCOUNT_ZERO;
 };
 
 Amount.prototype.is_zero = function() {
@@ -532,7 +532,7 @@ Amount.prototype.parse_human = function(j, options) {
 };
 
 Amount.prototype.parse_issuer = function(issuer) {
-  this._issuer = UInt160.from_json(issuer);
+  this._issuer = issuer;
   return this;
 };
 
@@ -583,7 +583,7 @@ function(quality, counterCurrency, counterIssuer, opts) {
   const offset = parseInt(offset_hex, 16) - 100;
 
   this._currency = Currency.from_json(counterCurrency);
-  this._issuer = UInt160.from_json(counterIssuer);
+  this._issuer = counterIssuer;
   this._is_native = this._currency.is_native();
 
   if (this._is_native && baseCurrency.is_native()) {
@@ -643,7 +643,7 @@ function(quality, counterCurrency, counterIssuer, opts) {
 Amount.prototype.parse_number = function(n) {
   this._is_native = false;
   this._currency = Currency.from_json(1);
-  this._issuer = UInt160.from_json(1);
+  this._issuer = ACCOUNT_ONE;
   this._set_value(new IOUValue(n));
   return this;
 };
@@ -659,15 +659,15 @@ Amount.prototype.parse_json = function(j) {
       if (m) {
         this._currency = Currency.from_json(m[2]);
         if (m[3]) {
-          this._issuer = UInt160.from_json(m[3]);
+          this._issuer = m[3];
         } else {
-          this._issuer = UInt160.from_json('1');
+          this._issuer = 'NaN';
         }
         this.parse_value(m[1]);
       } else {
         this.parse_native(j);
         this._currency = Currency.from_json('0');
-        this._issuer = UInt160.from_json('0');
+        this._issuer = ACCOUNT_ZERO;
       }
       break;
 
@@ -686,9 +686,10 @@ Amount.prototype.parse_json = function(j) {
         // Parse the passed value to sanitize and copy it.
         this._currency.parse_json(j.currency, true); // Never XRP.
 
-        if (typeof j.issuer === 'string') {
-          this._issuer.parse_json(j.issuer);
+        if (typeof j.issuer !== 'string') {
+          throw new Error('issuer must be a string');
         }
+        this._issuer = j.issuer;
 
         this.parse_value(j.value);
       }
@@ -736,12 +737,7 @@ Amount.prototype.set_currency = function(c) {
 };
 
 Amount.prototype.set_issuer = function(issuer) {
-  if (issuer instanceof UInt160) {
-    this._issuer = issuer;
-  } else {
-    this._issuer = UInt160.from_json(issuer);
-  }
-
+  this._issuer = issuer;
   return this;
 };
 
@@ -939,7 +935,7 @@ Amount.prototype.to_human_full = function(options) {
   const opts = options || {};
   const value = this.to_human(opts);
   const currency = this._currency.to_human();
-  const issuer = this._issuer.to_json(opts);
+  const issuer = this._issuer;
   const base = value + '/' + currency;
   return this.is_native() ? base : (base + '/' + issuer);
 };
@@ -955,21 +951,21 @@ Amount.prototype.to_json = function() {
     this._currency.to_hex() : this._currency.to_json()
   };
 
-  if (this._issuer.is_valid()) {
-    amount_json.issuer = this._issuer.to_json();
+  if (isValidAddress(this._issuer)) {
+    amount_json.issuer = this._issuer;
   }
 
   return amount_json;
 };
 
-Amount.prototype.to_text_full = function(opts) {
+Amount.prototype.to_text_full = function() {
   if (!this.is_valid()) {
     return 'NaN';
   }
   return this._is_native
       ? this.to_human() + '/XRP'
       : this.to_text() + '/' + this._currency.to_json()
-        + '/' + this._issuer.to_json(opts);
+        + '/' + this._issuer;
 };
 
 // For debugging.
@@ -998,11 +994,8 @@ Amount.prototype.not_equals_why = function(d, ignore_issuer) {
     if (!this._currency.equals(d._currency)) {
       return 'Non-XRP currency differs.';
     }
-    if (!ignore_issuer && !this._issuer.equals(d._issuer)) {
-      return 'Non-XRP issuer differs: '
-      + d._issuer.to_json()
-      + '/'
-      + this._issuer.to_json();
+    if (!ignore_issuer && this._issuer !== d._issuer) {
+      return 'Non-XRP issuer differs: ' + d._issuer + '/' + this._issuer;
     }
   }
 };
diff --git a/src/core/constants.js b/src/core/constants.js
new file mode 100644
index 00000000..3adbdbf9
--- /dev/null
+++ b/src/core/constants.js
@@ -0,0 +1,6 @@
+'use strict';
+
+module.exports = {
+  ACCOUNT_ZERO: 'rrrrrrrrrrrrrrrrrrrrrhoLvTp',
+  ACCOUNT_ONE: 'rrrrrrrrrrrrrrrrrrrrBZbvji'
+};
diff --git a/src/core/meta.js b/src/core/meta.js
index c4f9b781..d1b026c3 100644
--- a/src/core/meta.js
+++ b/src/core/meta.js
@@ -1,7 +1,10 @@
-var extend  = require('extend');
-var utils = require('./utils');
-var UInt160 = require('./uint160').UInt160;
-var Amount  = require('./amount').Amount;
+'use strict';
+const extend = require('extend');
+const utils = require('./utils');
+const UInt160 = require('./uint160').UInt160;
+const Amount = require('./amount').Amount;
+const ACCOUNT_ZERO = require('./constants').ACCOUNT_ZERO;
+const {isValidAddress} = require('ripple-address-codec');
 
 /**
  * Meta data processing facility
@@ -11,8 +14,6 @@ var Amount  = require('./amount').Amount;
  */
 
 function Meta(data) {
-  var self = this;
-
   this.nodes = [ ];
 
   if (typeof data !== 'object') {
@@ -24,7 +25,7 @@ function Meta(data) {
   }
 
   data.AffectedNodes.forEach(this.addNode, this);
-};
+}
 
 Meta.NODE_TYPES = [
   'CreatedNode',
@@ -53,10 +54,10 @@ Meta.ACCOUNT_FIELDS = [
  */
 
 Meta.prototype.getNodeType = function(node) {
-  var result = null;
+  let result = null;
 
-  for (var i=0; i<Meta.NODE_TYPES.length; i++) {
-    var type = Meta.NODE_TYPES[i];
+  for (let i = 0; i < Meta.NODE_TYPES.length; i++) {
+    const type = Meta.NODE_TYPES[i];
     if (node.hasOwnProperty(type)) {
       result = type;
       break;
@@ -83,20 +84,22 @@ Meta.prototype.isAccountField = function(field) {
  */
 
 Meta.prototype.addNode = function(node) {
-  this._affectedAccounts = void(0);
-  this._affectedBooks = void(0);
+  this._affectedAccounts = undefined;
+  this._affectedBooks = undefined;
 
-  var result = { };
+  const result = { };
 
-  if ((result.nodeType = this.getNodeType(node))) {
-    node = node[result.nodeType];
-    result.diffType    = result.nodeType;
-    result.entryType   = node.LedgerEntryType;
-    result.ledgerIndex = node.LedgerIndex;
-    result.fields      = extend({ }, node.PreviousFields, node.NewFields, node.FinalFields);
-    result.fieldsPrev  = node.PreviousFields || { };
-    result.fieldsNew   = node.NewFields || { };
-    result.fieldsFinal = node.FinalFields || { };
+  result.nodeType = this.getNodeType(node);
+  if (result.nodeType) {
+    const _node = node[result.nodeType];
+    result.diffType = result.nodeType;
+    result.entryType = _node.LedgerEntryType;
+    result.ledgerIndex = _node.LedgerIndex;
+    result.fields = extend({ }, _node.PreviousFields,
+      _node.NewFields, _node.FinalFields);
+    result.fieldsPrev = _node.PreviousFields || { };
+    result.fieldsNew = _node.NewFields || { };
+    result.fieldsFinal = _node.FinalFields || { };
 
     // getAffectedBooks will set this
     // result.bookKey   = undefined;
@@ -126,36 +129,36 @@ Meta.prototype.getNodes = function(options) {
       }
       return true;
     });
-  } else {
-    return this.nodes;
   }
+  return this.nodes;
 };
 
-Meta.prototype.getAffectedAccounts = function(from) {
+Meta.prototype.getAffectedAccounts = function() {
   if (this._affectedAccounts) {
     return this._affectedAccounts;
   }
 
-  var accounts = [ ];
+  const accounts = [ ];
 
   // This code should match the behavior of the C++ method:
   // TransactionMetaSet::getAffectedAccounts
-  for (var i=0; i<this.nodes.length; i++) {
-    var node = this.nodes[i];
-    var fields = (node.nodeType === 'CreatedNode')
+  for (let i = 0; i < this.nodes.length; i++) {
+    const node = this.nodes[i];
+    const fields = (node.nodeType === 'CreatedNode')
     ? node.fieldsNew
     : node.fieldsFinal;
 
-    for (var fieldName in fields) {
-      var field = fields[fieldName];
+    for (const fieldName in fields) {
+      const field = fields[fieldName];
 
       if (this.isAccountField(fieldName) && UInt160.is_valid(field)) {
         accounts.push(field);
-      } else if (~Meta.AMOUNT_FIELDS_AFFECTING_ISSUER.indexOf(fieldName)) {
-        var amount = Amount.from_json(field);
-        var issuer = amount.issuer();
-        if (issuer.is_valid() && !issuer.is_zero()) {
-          accounts.push(issuer.to_json());
+      } else if (
+          Meta.AMOUNT_FIELDS_AFFECTING_ISSUER.indexOf(fieldName) !== -1) {
+        const amount = Amount.from_json(field);
+        const issuer = amount.issuer();
+        if (isValidAddress(issuer) && issuer !== ACCOUNT_ZERO) {
+          accounts.push(issuer);
         }
       }
     }
@@ -171,29 +174,29 @@ Meta.prototype.getAffectedBooks = function() {
     return this._affectedBooks;
   }
 
-  var books = [ ];
+  const books = [ ];
 
-  for (var i=0; i<this.nodes.length; i++) {
-    var node = this.nodes[i];
+  for (let i = 0; i < this.nodes.length; i++) {
+    const node = this.nodes[i];
 
     if (node.entryType !== 'Offer') {
       continue;
     }
 
-    var gets = Amount.from_json(node.fields.TakerGets);
-    var pays = Amount.from_json(node.fields.TakerPays);
-    var getsKey = gets.currency().to_json();
-    var paysKey = pays.currency().to_json();
+    const gets = Amount.from_json(node.fields.TakerGets);
+    const pays = Amount.from_json(node.fields.TakerPays);
+    let getsKey = gets.currency().to_json();
+    let paysKey = pays.currency().to_json();
 
     if (getsKey !== 'XRP') {
-      getsKey += '/' + gets.issuer().to_json();
+      getsKey += '/' + gets.issuer();
     }
 
     if (paysKey !== 'XRP') {
-      paysKey += '/' + pays.issuer().to_json();
+      paysKey += '/' + pays.issuer();
     }
 
-    var key = getsKey + ':' + paysKey;
+    const key = getsKey + ':' + paysKey;
 
     // Hell of a lot of work, so we are going to cache this. We can use this
     // later to good effect in OrderBook.notify to make sure we only process
@@ -243,12 +246,12 @@ Meta.prototype.getAffectedBooks = function() {
  */
 
 [
- 'forEach',
- 'map',
- 'filter',
- 'every',
- 'some',
- 'reduce'
+  'forEach',
+  'map',
+  'filter',
+  'every',
+  'some',
+  'reduce'
 ].forEach(function(fn) {
   Meta.prototype[fn] = function() {
     return Array.prototype[fn].apply(this.nodes, arguments);
diff --git a/src/core/orderbookutils.js b/src/core/orderbookutils.js
index ec9eb90e..462bc333 100644
--- a/src/core/orderbookutils.js
+++ b/src/core/orderbookutils.js
@@ -29,8 +29,7 @@ function createAmount(value, currency_, counterparty_) {
     Currency.from_json(currency_);
 
   const counterparty = counterparty_ instanceof UInt160 ?
-    counterparty_ :
-    UInt160.from_json(counterparty_);
+    counterparty_.to_json() : counterparty_;
 
   return Amount.from_components_unsafe(new IOUValue(value),
     currency, counterparty, false);
diff --git a/src/core/serializedtypes.js b/src/core/serializedtypes.js
index f8787d46..ce0298bd 100644
--- a/src/core/serializedtypes.js
+++ b/src/core/serializedtypes.js
@@ -100,7 +100,8 @@ SerializedType.serialize_varint = function(so, val) {
 
 SerializedType.prototype.parse_varint = function(so) {
   const b1 = so.read(1)[0];
-  let b2, b3;
+  let b2;
+  let b3;
   let result;
 
   if (b1 > 254) {
@@ -416,7 +417,8 @@ exports.Quality = new SerializedType({
       value = new BigNumber(val);
     }
 
-    let hi = 0, lo = 0;
+    let hi = 0;
+    let lo = 0;
 
     const offset = value.e - 15;
     if (val !== 0) {
@@ -483,7 +485,8 @@ const STAmount = exports.Amount = new SerializedType({
         valueBytes[0] |= 0x40;
       }
     } else {
-      let hi = 0, lo = 0;
+      let hi = 0;
+      let lo = 0;
 
       // First bit: non-native
       hi |= 1 << 31;
@@ -518,7 +521,7 @@ const STAmount = exports.Amount = new SerializedType({
       STCurrency.serialize(so, currency, true);
 
       // Issuer (160-bit hash)
-      so.append(amount.issuer().to_bytes());
+      so.append(UInt160.from_json(amount.issuer()).to_bytes());
     }
   },
   parse: function(so) {
@@ -834,7 +837,7 @@ exports.STMemo = new SerializedType({
           output.parsed_memo_data = convertHexToString(output.MemoData);
         }
         /* eslint-disable no-empty */
-      } catch(e) {
+      } catch (e) {
         // empty
         // we'll fail in case the content does not match what the MemoFormat
         // described
diff --git a/src/core/transaction.js b/src/core/transaction.js
index 90e455fe..0a54b4cb 100644
--- a/src/core/transaction.js
+++ b/src/core/transaction.js
@@ -14,6 +14,7 @@ const SerializedObject = require('./serializedobject').SerializedObject;
 const RippleError = require('./rippleerror').RippleError;
 const hashprefixes = require('./hashprefixes');
 const log = require('./log').internal.sub('transaction');
+const {isValidAddress} = require('ripple-address-codec');
 
 /**
  * @constructor Transaction
@@ -722,7 +723,7 @@ Transaction.prototype._setAmount = function(name, amount, options_) {
   if (!(isNative || parsedAmount.currency().is_valid())) {
     throw new Error(name + ' must have a valid currency');
   }
-  if (!(isNative || parsedAmount.issuer().is_valid())) {
+  if (!(isNative || isValidAddress(parsedAmount.issuer()))) {
     throw new Error(name + ' must have a valid issuer');
   }
 
diff --git a/src/core/transactionmanager.js b/src/core/transactionmanager.js
index 3406e30f..fb5c241d 100644
--- a/src/core/transactionmanager.js
+++ b/src/core/transactionmanager.js
@@ -21,7 +21,7 @@ function TransactionManager(account) {
   const self = this;
 
   this._account = account;
-  this._accountID = account._account_id;
+  this._accountID = account._address;
   this._remote = account._remote;
   this._nextSequence = undefined;
   this._maxFee = this._remote.max_fee;