diff --git a/lib/model/txproposal.js b/lib/model/txproposal.js
index de24a35..4998ed9 100644
--- a/lib/model/txproposal.js
+++ b/lib/model/txproposal.js
@@ -13,6 +13,7 @@ var Common = require('../common');
 var Constants = Common.Constants;
 var Defaults = Common.Defaults;
 
+var TxProposalLegacy = require('./txproposal_legacy');
 var TxProposalAction = require('./txproposalaction');
 
 function TxProposal() {};
@@ -67,7 +68,7 @@ TxProposal.create = function(opts) {
 
 TxProposal.fromObj = function(obj) {
   if (!(obj.version >= 3)) {
-    throw new Error('TxProposal < v3 no longer supported.')
+    return TxProposalLegacy.fromObj(obj);
   }
 
   var x = new TxProposal();
diff --git a/lib/model/txproposal_legacy.js b/lib/model/txproposal_legacy.js
new file mode 100644
index 0000000..697c029
--- /dev/null
+++ b/lib/model/txproposal_legacy.js
@@ -0,0 +1,176 @@
+'use strict';
+
+var _ = require('lodash');
+var $ = require('preconditions').singleton();
+var log = require('npmlog');
+log.debug = log.verbose;
+log.disableColor();
+
+var Bitcore = require('bitcore-lib');
+
+var Common = require('../common');
+var Constants = Common.Constants;
+var Defaults = Common.Defaults;
+
+var TxProposalAction = require('./txproposalaction');
+
+function TxProposal() {};
+
+TxProposal.Types = {
+  SIMPLE: 'simple',
+  MULTIPLEOUTPUTS: 'multiple_outputs',
+  EXTERNAL: 'external'
+};
+
+TxProposal.fromObj = function(obj) {
+  var x = new TxProposal();
+
+  x.version = obj.version;
+  if (obj.version === '1.0.0') {
+    x.type = TxProposal.Types.SIMPLE;
+  } else {
+    x.type = obj.type;
+  }
+  x.createdOn = obj.createdOn;
+  x.id = obj.id;
+  x.walletId = obj.walletId;
+  x.creatorId = obj.creatorId;
+  x.outputs = obj.outputs;
+  x.toAddress = obj.toAddress;
+  x.amount = obj.amount;
+  x.message = obj.message;
+  x.payProUrl = obj.payProUrl;
+  x.proposalSignature = obj.proposalSignature;
+  x.changeAddress = obj.changeAddress;
+  x.inputs = obj.inputs;
+  x.requiredSignatures = obj.requiredSignatures;
+  x.requiredRejections = obj.requiredRejections;
+  x.walletN = obj.walletN;
+  x.status = obj.status;
+  x.txid = obj.txid;
+  x.broadcastedOn = obj.broadcastedOn;
+  x.inputPaths = obj.inputPaths;
+  x.actions = _.map(obj.actions, function(action) {
+    return TxProposalAction.fromObj(action);
+  });
+  x.outputOrder = obj.outputOrder;
+  x.network = obj.network;
+  x.fee = obj.fee;
+  x.feePerKb = obj.feePerKb;
+  x.excludeUnconfirmedUtxos = obj.excludeUnconfirmedUtxos;
+  x.proposalSignaturePubKey = obj.proposalSignaturePubKey;
+  x.proposalSignaturePubKeySig = obj.proposalSignaturePubKeySig;
+  x.addressType = obj.addressType || Constants.SCRIPT_TYPES.P2SH;
+  x.derivationStrategy = obj.derivationStrategy || Constants.DERIVATION_STRATEGIES.BIP45;
+  x.customData = obj.customData;
+
+  return x;
+};
+
+function throwUnsupportedError() {
+  var msg = 'Unsupported operation on this transaction proposal';
+  log.warn('DEPRECATED: ' + msg);
+  throw new Error(msg);
+};
+
+TxProposal.prototype.toObject = function() {
+  var x = _.cloneDeep(this);
+  x.isPending = this.isPending();
+  return x;
+};
+
+TxProposal.prototype._updateStatus = function() {
+  if (this.status != 'pending') return;
+
+  if (this.isRejected()) {
+    this.status = 'rejected';
+  } else if (this.isAccepted()) {
+    this.status = 'accepted';
+  }
+};
+
+TxProposal.prototype.getBitcoreTx = function() {
+  throwUnsupportedError();
+};
+
+TxProposal.prototype.getNetworkName = function() {
+  return Bitcore.Address(this.changeAddress.address).toObject().network;
+};
+
+TxProposal.prototype.getRawTx = function() {
+  throwUnsupportedError();
+};
+
+TxProposal.prototype.getTotalAmount = function() {
+  if (this.type == TxProposal.Types.MULTIPLEOUTPUTS || this.type == TxProposal.Types.EXTERNAL) {
+    return _.pluck(this.outputs, 'amount')
+      .reduce(function(total, n) {
+        return total + n;
+      }, 0);
+  } else {
+    return this.amount;
+  }
+};
+
+TxProposal.prototype.getActors = function() {
+  return _.pluck(this.actions, 'copayerId');
+};
+
+TxProposal.prototype.getApprovers = function() {
+  return _.pluck(
+    _.filter(this.actions, {
+      type: 'accept'
+    }), 'copayerId');
+};
+
+TxProposal.prototype.getActionBy = function(copayerId) {
+  return _.find(this.actions, {
+    copayerId: copayerId
+  });
+};
+
+TxProposal.prototype.addAction = function(copayerId, type, comment, signatures, xpub) {
+  var action = TxProposalAction.create({
+    copayerId: copayerId,
+    type: type,
+    signatures: signatures,
+    xpub: xpub,
+    comment: comment,
+  });
+  this.actions.push(action);
+  this._updateStatus();
+};
+
+TxProposal.prototype.sign = function() {
+  throwUnsupportedError();
+};
+
+TxProposal.prototype.reject = function(copayerId, reason) {
+  this.addAction(copayerId, 'reject', reason);
+};
+
+TxProposal.prototype.isPending = function() {
+  return !_.contains(['broadcasted', 'rejected'], this.status);
+};
+
+TxProposal.prototype.isAccepted = function() {
+  var votes = _.countBy(this.actions, 'type');
+  return votes['accept'] >= this.requiredSignatures;
+};
+
+TxProposal.prototype.isRejected = function() {
+  var votes = _.countBy(this.actions, 'type');
+  return votes['reject'] >= this.requiredRejections;
+};
+
+TxProposal.prototype.isBroadcasted = function() {
+  return this.status == 'broadcasted';
+};
+
+TxProposal.prototype.setBroadcasted = function() {
+  $.checkState(this.txid);
+  this.status = 'broadcasted';
+  this.broadcastedOn = Math.floor(Date.now() / 1000);
+};
+
+module.exports = TxProposal;
diff --git a/lib/server.js b/lib/server.js
index b6dcaba..0a9a703 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -1338,12 +1338,10 @@ WalletService.prototype._checkTx = function(txp) {
   var bitcoreError;
 
   var serializationOpts = {
-    disableIsFullySigned: true
+    disableIsFullySigned: true,
+    disableSmallFees: true,
+    disableLargeFees: true,
   };
-  if (!_.startsWith(txp.version, '1.')) {
-    serializationOpts.disableSmallFees = true;
-    serializationOpts.disableLargeFees = true;
-  }
 
   if (txp.getEstimatedSize() / 1000 > Defaults.MAX_TX_SIZE_IN_KB)
     return Errors.TX_MAX_SIZE_EXCEEDED;
@@ -1894,7 +1892,12 @@ WalletService.prototype.publishTx = function(opts, cb) {
 
         var copayer = wallet.getCopayer(self.copayerId);
 
-        var raw = txp.getRawTx();
+        var raw;
+        try {
+          raw = txp.getRawTx();
+        } catch (ex) {
+          return cb(ex);
+        }
         var signingKey = self._getSigningKey(raw, opts.proposalSignature, copayer.requestPubKeys);
         if (!signingKey) {
           return cb(new ClientError('Invalid proposal signature'));
@@ -2143,16 +2146,21 @@ WalletService.prototype.signTx = function(opts, cb) {
 
       var copayer = wallet.getCopayer(self.copayerId);
 
-      if (!txp.sign(self.copayerId, opts.signatures, copayer.xPubKey)) {
-        log.warn('Error signing transaction (BAD_SIGNATURES)');
-        log.warn('Wallet id:', self.walletId);
-        log.warn('Copayer id:', self.copayerId);
-        log.warn('Client version:', self.clientVersion);
-        log.warn('Arguments:', JSON.stringify(opts));
-        log.warn('Transaction proposal:', JSON.stringify(txp));
-        var raw = txp.getBitcoreTx().uncheckedSerialize();
-        log.warn('Raw tx:', raw);
-        return cb(Errors.BAD_SIGNATURES);
+      try {
+        if (!txp.sign(self.copayerId, opts.signatures, copayer.xPubKey)) {
+          log.warn('Error signing transaction (BAD_SIGNATURES)');
+          log.warn('Wallet id:', self.walletId);
+          log.warn('Copayer id:', self.copayerId);
+          log.warn('Client version:', self.clientVersion);
+          log.warn('Arguments:', JSON.stringify(opts));
+          log.warn('Transaction proposal:', JSON.stringify(txp));
+          var raw = txp.getBitcoreTx().uncheckedSerialize();
+          log.warn('Raw tx:', raw);
+          return cb(Errors.BAD_SIGNATURES);
+        }
+      } catch (ex) {
+        log.error('Error signing transaction proposal', ex);
+        return cb(ex);
       }
 
       self.storage.storeTx(self.walletId, txp, function(err) {