diff --git a/lib/bcoin/wallet.js b/lib/bcoin/wallet.js
index ff87724c..f0968458 100644
--- a/lib/bcoin/wallet.js
+++ b/lib/bcoin/wallet.js
@@ -74,8 +74,10 @@ function Wallet(options) {
   this.purposeKeys = options.purposeKeys || [];
   this.keys = options.keys || [];
 
+  this.normal = false;
   this.hd = false;
-  this.hdpm = false;
+  this.bip44 = false;
+  this.bip45 = false;
   this.multisig = false;
 
   this.type = options.type || 'pubkeyhash';
@@ -94,11 +96,15 @@ function Wallet(options) {
       this.subtype = 'multisig';
   }
 
-  if (this.master)
+  if (this.master) {
     this.hd = true;
-
-  if (this.master && this.type === 'scripthash' && this.subtype === 'multisig')
-    this.hdpm = true;
+    if (this.type === 'scripthash' && this.subtype === 'multisig')
+      this.bip45 = true;
+    else
+      this.bip44 = true;
+  } else {
+    this.normal = true;
+  }
 
   if (this.type === 'multisig' || this.subtype === 'multisig')
     this.multisig = true;
@@ -112,12 +118,12 @@ function Wallet(options) {
   if (this.n < 1 || this.n > this.nmax)
     throw new Error('n ranges between 1 and ' + this.nmax);
 
-  if (this.hdpm) {
-    this.purposeKey = this.master.hd.isPublic
+  if (this.bip45) {
+    this.purposeKey = this.master.hd.isPurpose45()
       ? this.master.hd
       : this.master.hd.derivePurpose45();
   } else if (this.hd) {
-    this.accountKey = this.master.hd.isPublic
+    this.accountKey = this.master.hd.isAccount44()
       ? this.master.hd
       : this.master.hd.deriveAccount44(this.accountIndex);
   }
@@ -151,20 +157,54 @@ function Wallet(options) {
   this.loading = true;
   this.lastTs = 0;
 
-  if (!this.hdpm) {
-    if (options.addresses.length) {
-      this.current = bcoin.address(options.addresses[options.addresses.length - 1]);
-      this._firstKey = {
-        priv: this.current.key._key.getPrivate().toArray(),
-        pub: this.current.key._key.getPublic(true, 'array')
-      };
+  var key, receiving;
+
+  // This is a chicken and egg problem for BIP45. Real address keys cannot be
+  // generated until all shared keys have been added to the wallet. The flow of
+  // this wallet is, the actual address objects will be generated once all
+  // shared keys have been added. This presents a problem for non-bip45
+  // wallets: if they want to use the addKey() interface with
+  // wallet.getPublicKey(), we need to expose a key for them to use. Here, we
+  // generate the last receiving address. However, since "normal" wallets
+  // cannot deterministically generate keys, we have to buffer the generated
+  // key for later.
+  if (!this.bip45) {
+    if (this.hd) {
+      // Generate the last known receiving address
+      key = this.createKey(false, Math.max(0, this.addressDepth - 1));
+      this.current = bcoin.address({
+        priv: key.priv,
+        type: this.type,
+        subtype: this.subtype,
+        m: this.m,
+        n: this.n,
+        keys: options.keys
+      });
     } else {
-      this._firstKey = this.createKey(false, Math.max(0, this.addressDepth - 1));
-      this.current = bcoin.address({ priv: this._firstKey.priv });
+      // Try to find the last receiving address if there is one.
+      receiving = options.addresses.filter(function(address) {
+        return !address.change && (address.priv || address.pub || address.key);
+      }).pop();
+      if (receiving) {
+        this.current = bcoin.address(receiving);
+      } else {
+        // No receiving address is in this wallet yet, generate
+        // it and save it so createKey can recreate it later.
+        key = this.createKey();
+        this._firstKey = key;
+        this.current = bcoin.address({
+          priv: key.priv,
+          type: this.type,
+          subtype: this.subtype,
+          m: this.m,
+          n: this.n,
+          keys: options.keys
+        });
+      }
     }
   }
 
-  if (this.hdpm)
+  if (this.bip45)
     this.addKey(this.purposeKey);
   else
     this.addKey(this.current.publicKey);
@@ -176,50 +216,61 @@ function Wallet(options) {
 
 inherits(Wallet, EventEmitter);
 
+// Wallet ID:
+// bip45: Purpose key address
+// HD: Account key address
+// Normal: Address of first key in wallet
+Wallet.prototype.getID = function() {
+  if (this.bip45)
+    return bcoin.address.key2addr(this.purposeKey.publicKey);
+
+  if (this.hd)
+    return bcoin.address.key2addr(this.accountKey.publicKey);
+
+  if (this.addresses.length)
+    return this.addresses[0].getKeyAddress();
+
+  if (this._firstKey)
+    return bcoin.address.key2addr(this._firstKey.pub);
+
+  assert(false);
+};
+
 Wallet.prototype._initAddresses = function() {
   var options = this.options;
 
+  assert(!this._initialized);
+  this._initialized = true;
+
   options.addresses.forEach(function(address) {
     address = this.addAddress(address);
-    if (!address.change)
-      this.current = address;
+    if (!this.hd) {
+      if (!address.change)
+        this.current = address;
+      else
+        this.changeAddress = address;
+    }
   }, this);
 
   if (this.hd) {
     for (i = 0; i < this.addressDepth; i++)
-      this.createAddress(false, i);
+      this.current = this.createAddress(false, i);
 
     for (i = 0; i < this.changeDepth; i++)
-      this.createAddress(true, i);
+      this.changeAddress = this.createAddress(true, i);
   }
 
-  // Create a non-master account address if we don't have one.
-  if (this.addresses.length === 0)
-    this.createAddress();
+  if (!this.current)
+    this.current = this.createAddress();
 
-  // Find the last change address if there is one.
-  if (this.hd) {
-    if (this.changeDepth === 0)
-      this.changeAddress = this.createAddress(true);
-    else
-      this.changeAddress = this.addresses[this.addresses.length - 1];
-  } else {
-    for (i = this.addresses.length - 1; i >= 0; i--) {
-      if (this.addresses[i].change)
-        break;
-    }
-
-    if (i === -1)
-      this.changeAddress = this.createAddress(true);
-    else
-      this.changeAddress = this.addresses[i];
-  }
+  if (!this.changeAddress)
+    this.changeAddress = this.createAddress(true);
 
   assert(this.current);
   assert(!this.current.change);
   assert(this.changeAddress.change);
 
-  this.prefix = 'bt/wallet/' + this.getKeyAddress() + '/';
+  this.prefix = 'bt/wallet/' + this.getID() + '/';
 
   this.tx = new bcoin.txPool(this);
 
@@ -245,9 +296,9 @@ Wallet.prototype.addKey = function addKey(key) {
     key = hdKey.publicKey;
   }
 
-  if (this.hdpm) {
+  if (this.bip45) {
     if (!hdKey || !hdKey.isPurpose45())
-      throw new Error('Must add HD purpose keys to HD wallet.');
+      throw new Error('Must add HD purpose keys to BIP45 wallet.');
 
     has = this.purposeKeys.some(function(pub) {
       return pub.xpubkey === hdKey.xpubkey;
@@ -256,6 +307,8 @@ Wallet.prototype.addKey = function addKey(key) {
     if (has)
       return;
 
+    assert(!this._keysFinalized);
+
     this.purposeKeys.push(hdKey);
 
     if (this.purposeKeys.length === this.n)
@@ -273,6 +326,8 @@ Wallet.prototype.addKey = function addKey(key) {
   if (has)
     return;
 
+  assert(!this._keysFinalized);
+
   this.keys.push(key);
 
   if (this.keys.length === this.n)
@@ -280,11 +335,14 @@ Wallet.prototype.addKey = function addKey(key) {
 };
 
 Wallet.prototype.finalizeKeys = function finalizeKeys(key) {
-  if (this.hdpm) {
+  assert(!this._keysFinalized);
+  this._keysFinalized = true;
+
+  if (this.bip45) {
     this.purposeKeys = utils.sortHDKeys(this.purposeKeys);
 
     for (i = 0; i < this.purposeKeys.length; i++) {
-      if (utils.isEqual(this.purposeKeys[i].publicKey, this.purposeKey.publicKey)) {
+      if (this.purposeKeys[i].xpubkey === this.purposeKey.xpubkey) {
         this.cosignerIndex = i;
         break;
       }
@@ -302,6 +360,8 @@ Wallet.prototype.finalizeKeys = function finalizeKeys(key) {
 Wallet.prototype.removeKey = function removeKey(key) {
   var hdKey, index;
 
+  assert(!this._keysFinalized);
+
   if (bcoin.hd.priv.isExtended(key))
     key = bcoin.hd.priv(key);
   else if (bcoin.hd.pub.isExtended(key))
@@ -318,9 +378,9 @@ Wallet.prototype.removeKey = function removeKey(key) {
     key = hd.publicKey;
   }
 
-  if (this.hdpm) {
+  if (this.bip45) {
     if (!hdKey || !hdKey.isPurpose45())
-      throw new Error('Must add HD purpose keys to HD wallet.');
+      throw new Error('Must add HD purpose keys to BIP45 wallet.');
 
     index = this.purposeKeys.map(function(pub, i) {
       return pub.xpubkey === hdKey.xpubkey ? i : null;
@@ -369,11 +429,13 @@ Wallet.prototype._init = function init() {
   });
 
   this.tx.on('tx', function(tx) {
-    // TX using this change address was
-    // confirmed. Allocate a new change address.
+    // TX using this address was confirmed.
+    // Allocate a new address.
     if (tx.block) {
+      if (self.current.ownOutput(tx))
+        self.current = self.createAddress();
       if (self.changeAddress.ownOutput(tx))
-        self.changeAddress = self.createChangeAddress();
+        self.changeAddress = self.createAddress(true);
     }
     self.emit('tx', tx);
   });
@@ -432,6 +494,8 @@ Wallet.prototype.createAddress = function createAddress(change, index) {
   var key = this.createKey(change, index);
   var address;
 
+  assert(this._initialized);
+
   var options = {
     priv: key.priv,
     pub: key.pub,
@@ -443,7 +507,7 @@ Wallet.prototype.createAddress = function createAddress(change, index) {
     change: change
   };
 
-  if (this.hdpm) {
+  if (this.bip45) {
     this.purposeKeys.forEach(function(key, cosignerIndex) {
       key = key
         .derive(cosignerIndex)
@@ -469,9 +533,6 @@ Wallet.prototype.createAddress = function createAddress(change, index) {
 
   address = this.addAddress(options);
 
-  if (!change)
-    this.current = address;
-
   return address;
 };
 
@@ -492,6 +553,8 @@ Wallet.prototype.addAddress = function addAddress(address) {
   var self = this;
   var index;
 
+  assert(this._initialized);
+
   if (!(address instanceof bcoin.address))
     address = bcoin.address(address);
 
@@ -527,6 +590,8 @@ Wallet.prototype.addAddress = function addAddress(address) {
 Wallet.prototype.removeAddress = function removeAddress(address) {
   var i;
 
+  assert(this._initialized);
+
   assert(address instanceof bcoin.address);
 
   i = this._addressIndex(address);
@@ -595,7 +660,7 @@ Wallet.prototype.createKey = function createKey(change, index) {
   if (index == null)
     index = change ? this.changeDepth : this.addressDepth;
 
-  if (this.hdpm) {
+  if (this.bip45) {
     key = this.purposeKey
       .derive(this.cosignerIndex)
       .derive(change ? 1 : 0)
@@ -642,6 +707,8 @@ Wallet.prototype.ownOutput = function ownOutput(tx, index) {
 Wallet.prototype.fill = function fill(tx, address, fee) {
   var unspent, items, result;
 
+  assert(this._initialized);
+
   if (!address)
     address = this.changeAddress.getKeyAddress();
 
@@ -841,23 +908,32 @@ Wallet.prototype.__defineGetter__('address', function() {
 });
 
 Wallet.prototype.toJSON = function toJSON(encrypt) {
+  assert(this._initialized);
   return {
     v: 3,
     name: 'wallet',
     network: network.type,
+    type: this.type,
+    subtype: this.subtype,
+    m: this.m,
+    n: this.n,
     accountIndex: this.accountIndex,
     addressDepth: this.addressDepth,
     changeDepth: this.changeDepth,
+    cosignerIndex: this.cosignerIndex,
+    keys: this.bip45
+      ? this.purposeKeys.map(function(key) {
+        return key.xpubkey;
+      })
+      : this.keys.map(function(key) {
+        return utils.toBase58(key);
+      }),
     master: this.master ? this.master.toJSON(encrypt) : null,
     addresses: this.addresses.filter(function(address) {
-      if (!address.key.hd)
-        return true;
-
-      if (address.change)
+      if (this.hd)
         return false;
-
       return true;
-    }).map(function(address) {
+    }, this).map(function(address) {
       return address.toJSON(encrypt);
     }),
     balance: utils.toBTC(this.getBalance()),
@@ -875,12 +951,18 @@ Wallet.fromJSON = function fromJSON(json, decrypt) {
     assert.equal(json.network, network.type);
 
   w = new Wallet({
+    type: json.type,
+    subtype: json.subtype,
+    m: json.m,
+    n: json.n,
     accountIndex: json.accountIndex,
     addressDepth: json.addressDepth,
     changeDepth: json.changeDepth,
+    cosignerIndex: json.cosignerIndex,
     master: json.master
       ? bcoin.address.fromJSON(json.master, decrypt)
       : null,
+    keys: json.keys,
     addresses: json.addresses.map(function(address) {
       return bcoin.address.fromJSON(address, decrypt);
     })
@@ -888,17 +970,6 @@ Wallet.fromJSON = function fromJSON(json, decrypt) {
 
   w.tx.fromJSON(json.tx);
 
-  // Make sure we have all the change
-  // addresses (we don't save them).
-  if (w.master) {
-    for (i = 0; i < w.changeDepth; i++) {
-      w.addAddress({
-        change: true,
-        priv: w.master.key.hd.deriveChange(w.accountIndex, i)
-      });
-    }
-  }
-
   return w;
 };