diff --git a/core/src/main/kotlin/net/corda/core/node/services/Services.kt b/core/src/main/kotlin/net/corda/core/node/services/Services.kt
index 536e032910..43d16f732b 100644
--- a/core/src/main/kotlin/net/corda/core/node/services/Services.kt
+++ b/core/src/main/kotlin/net/corda/core/node/services/Services.kt
@@ -6,6 +6,7 @@ import net.corda.core.contracts.*
 import net.corda.core.crypto.*
 import net.corda.core.flows.FlowException
 import net.corda.core.serialization.CordaSerializable
+import net.corda.core.serialization.OpaqueBytes
 import net.corda.core.toFuture
 import net.corda.core.transactions.LedgerTransaction
 import net.corda.core.transactions.TransactionBuilder
@@ -253,7 +254,7 @@ interface VaultService {
      * is implemented in a separate module (finance) and requires access to it.
      */
     @Suspendable
-    fun <T : ContractState> unconsumedStatesForSpending(amount: Amount<Currency>, onlyFromIssuerParties: Set<AbstractParty>? = null, notary: Party? = null, lockId: UUID): List<StateAndRef<T>>
+    fun <T : ContractState> unconsumedStatesForSpending(amount: Amount<Currency>, onlyFromIssuerParties: Set<AbstractParty>? = null, notary: Party? = null, lockId: UUID, withIssuerRefs: Set<OpaqueBytes>? = null): List<StateAndRef<T>>
 }
 
 inline fun <reified T: ContractState> VaultService.unconsumedStates(includeSoftLockedStates: Boolean = true): Iterable<StateAndRef<T>> =
diff --git a/finance/src/main/kotlin/net/corda/contracts/clause/AbstractConserveAmount.kt b/finance/src/main/kotlin/net/corda/contracts/clause/AbstractConserveAmount.kt
index 1863997635..67f0099766 100644
--- a/finance/src/main/kotlin/net/corda/contracts/clause/AbstractConserveAmount.kt
+++ b/finance/src/main/kotlin/net/corda/contracts/clause/AbstractConserveAmount.kt
@@ -4,6 +4,8 @@ import net.corda.core.contracts.*
 import net.corda.core.contracts.clauses.Clause
 import net.corda.core.crypto.CompositeKey
 import net.corda.core.transactions.TransactionBuilder
+import net.corda.core.utilities.loggerFor
+import net.corda.core.utilities.trace
 import java.util.*
 
 /**
@@ -12,6 +14,11 @@ import java.util.*
  * errors on no-match, ends on match.
  */
 abstract class AbstractConserveAmount<S : FungibleAsset<T>, C : CommandData, T : Any> : Clause<S, C, Issued<T>>() {
+
+    private companion object {
+        val log = loggerFor<AbstractConserveAmount<*,*,*>>()
+    }
+
     /**
      * Gather assets from the given list of states, sufficient to match or exceed the given amount.
      *
@@ -30,9 +37,12 @@ abstract class AbstractConserveAmount<S : FungibleAsset<T>, C : CommandData, T :
             gatheredAmount += Amount(c.state.data.amount.quantity, amount.token)
         }
 
-        if (gatheredAmount < amount)
+        if (gatheredAmount < amount) {
+            log.trace { "Insufficient balance: requested $amount, available $gatheredAmount" }
             throw InsufficientBalanceException(amount - gatheredAmount)
+        }
 
+        log.trace { "Gathered coins: requested $amount, available $gatheredAmount, change: ${gatheredAmount - amount}" }
         return Pair(gathered, gatheredAmount)
     }
 
@@ -61,7 +71,7 @@ abstract class AbstractConserveAmount<S : FungibleAsset<T>, C : CommandData, T :
         // highest total value
         acceptableCoins = acceptableCoins.filter { it.state.notary == tx.notary }
 
-        val (gathered, gatheredAmount) = gatherCoins(acceptableCoins, Amount(amount.quantity, currency))
+        val (gathered, gatheredAmount) = gatherCoins(acceptableCoins, amount)
         val takeChangeFrom = gathered.lastOrNull()
         val change = if (takeChangeFrom != null && gatheredAmount > amount) {
             Amount(gatheredAmount.quantity - amount.quantity, takeChangeFrom.state.data.amount.token)
diff --git a/finance/src/main/kotlin/net/corda/flows/CashExitFlow.kt b/finance/src/main/kotlin/net/corda/flows/CashExitFlow.kt
index c80903f95a..8a42262ef6 100644
--- a/finance/src/main/kotlin/net/corda/flows/CashExitFlow.kt
+++ b/finance/src/main/kotlin/net/corda/flows/CashExitFlow.kt
@@ -33,7 +33,7 @@ class CashExitFlow(val amount: Amount<Currency>, val issueRef: OpaqueBytes, prog
         progressTracker.currentStep = GENERATING_TX
         val builder: TransactionBuilder = TransactionType.General.Builder(null)
         val issuer = serviceHub.myInfo.legalIdentity.ref(issueRef)
-        val exitStates = serviceHub.vaultService.unconsumedStatesForSpending<Cash.State>(amount, setOf(issuer.party), builder.notary, builder.lockId)
+        val exitStates = serviceHub.vaultService.unconsumedStatesForSpending<Cash.State>(amount, setOf(issuer.party), builder.notary, builder.lockId, setOf(issuer.reference))
         try {
             Cash().generateExit(
                     builder,
diff --git a/node/src/main/kotlin/net/corda/node/services/vault/NodeVaultService.kt b/node/src/main/kotlin/net/corda/node/services/vault/NodeVaultService.kt
index 58b4a2dc5c..74163bd403 100644
--- a/node/src/main/kotlin/net/corda/node/services/vault/NodeVaultService.kt
+++ b/node/src/main/kotlin/net/corda/node/services/vault/NodeVaultService.kt
@@ -13,19 +13,13 @@ import net.corda.contracts.asset.Cash
 import net.corda.core.ThreadBox
 import net.corda.core.bufferUntilSubscribed
 import net.corda.core.contracts.*
-import net.corda.core.crypto.AbstractParty
-import net.corda.core.crypto.CompositeKey
-import net.corda.core.crypto.Party
-import net.corda.core.crypto.SecureHash
+import net.corda.core.crypto.*
 import net.corda.core.node.ServiceHub
 import net.corda.core.node.services.StatesNotAvailableException
 import net.corda.core.node.services.Vault
 import net.corda.core.node.services.VaultService
 import net.corda.core.node.services.unconsumedStates
-import net.corda.core.serialization.SingletonSerializeAsToken
-import net.corda.core.serialization.deserialize
-import net.corda.core.serialization.serialize
-import net.corda.core.serialization.storageKryo
+import net.corda.core.serialization.*
 import net.corda.core.tee
 import net.corda.core.transactions.TransactionBuilder
 import net.corda.core.transactions.WireTransaction
@@ -326,9 +320,11 @@ class NodeVaultService(private val services: ServiceHub, dataSourceProperties: P
     val spendLock: ReentrantLock = ReentrantLock()
 
     @Suspendable
-    override fun <T : ContractState> unconsumedStatesForSpending(amount: Amount<Currency>, onlyFromIssuerParties: Set<AbstractParty>?, notary: Party?, lockId: UUID): List<StateAndRef<T>> {
+    override fun <T : ContractState> unconsumedStatesForSpending(amount: Amount<Currency>, onlyFromIssuerParties: Set<AbstractParty>?, notary: Party?, lockId: UUID, withIssuerRefs: Set<OpaqueBytes>?): List<StateAndRef<T>> {
 
         val issuerKeysStr = onlyFromIssuerParties?.fold("") { left, right -> left + "('${right.owningKey.toBase58String()}')," }?.dropLast(1)
+        val issuerRefsStr = withIssuerRefs?.fold("") { left, right -> left + "('${right.bytes.toHexString()}')," }?.dropLast(1)
+
         var stateAndRefs = mutableListOf<StateAndRef<T>>()
 
         // TODO: Need to provide a database provider independent means of performing this function.
@@ -359,7 +355,9 @@ class NodeVaultService(private val services: ServiceHub, dataSourceProperties: P
                             (if (notary != null)
                                 " AND vs.notary_key = '${notary.owningKey.toBase58String()}'" else "") +
                             (if (issuerKeysStr != null)
-                                " AND ccs.issuer_key IN $issuerKeysStr" else "")
+                                " AND ccs.issuer_key IN ($issuerKeysStr)" else "") +
+                            (if (issuerRefsStr != null)
+                                " AND ccs.issuer_ref IN ($issuerRefsStr)" else "")
 
                     // Retrieve spendable state refs
                     val rs = statement.executeQuery(selectJoin)
diff --git a/node/src/test/kotlin/net/corda/node/services/vault/NodeVaultServiceTest.kt b/node/src/test/kotlin/net/corda/node/services/vault/NodeVaultServiceTest.kt
index 225f39aff2..d1dd8ed608 100644
--- a/node/src/test/kotlin/net/corda/node/services/vault/NodeVaultServiceTest.kt
+++ b/node/src/test/kotlin/net/corda/node/services/vault/NodeVaultServiceTest.kt
@@ -1,6 +1,7 @@
 package net.corda.node.services.vault
 
 import net.corda.contracts.asset.Cash
+import net.corda.contracts.asset.DUMMY_CASH_ISSUER
 import net.corda.contracts.testing.fillWithSomeTestCash
 import net.corda.core.contracts.*
 import net.corda.core.crypto.composite
@@ -8,11 +9,14 @@ import net.corda.core.node.services.StatesNotAvailableException
 import net.corda.core.node.services.TxWritableStorageService
 import net.corda.core.node.services.VaultService
 import net.corda.core.node.services.unconsumedStates
+import net.corda.core.serialization.OpaqueBytes
 import net.corda.core.transactions.SignedTransaction
 import net.corda.core.utilities.DUMMY_NOTARY
 import net.corda.core.utilities.LogHelper
 import net.corda.node.utilities.configureDatabase
 import net.corda.node.utilities.databaseTransaction
+import net.corda.testing.BOC
+import net.corda.testing.BOC_KEY
 import net.corda.testing.MEGA_CORP
 import net.corda.testing.MEGA_CORP_KEY
 import net.corda.testing.node.MockServices
@@ -304,6 +308,43 @@ class NodeVaultServiceTest {
         }
     }
 
+    @Test
+    fun `unconsumedStatesForSpending from two issuer parties`() {
+        databaseTransaction(database) {
+
+            services.fillWithSomeTestCash(100.DOLLARS, DUMMY_NOTARY, 1, 1, Random(0L), issuedBy = (DUMMY_CASH_ISSUER))
+            services.fillWithSomeTestCash(100.DOLLARS, DUMMY_NOTARY, 1, 1, Random(0L), issuedBy = (BOC.ref(1)), issuerKey = BOC_KEY)
+
+            val spendableStatesUSD = services.vaultService.unconsumedStatesForSpending<Cash.State>(200.DOLLARS, lockId = UUID.randomUUID(),
+                                        onlyFromIssuerParties = setOf(DUMMY_CASH_ISSUER.party, BOC)).toList()
+            spendableStatesUSD.forEach(::println)
+            assertThat(spendableStatesUSD).hasSize(2)
+            assertThat(spendableStatesUSD[0].state.data.amount.token.issuer).isEqualTo(DUMMY_CASH_ISSUER)
+            assertThat(spendableStatesUSD[1].state.data.amount.token.issuer).isEqualTo(BOC.ref(1))
+        }
+    }
+
+    @Test
+    fun `unconsumedStatesForSpending from specific issuer party and refs`() {
+        databaseTransaction(database) {
+
+            services.fillWithSomeTestCash(100.DOLLARS, DUMMY_NOTARY, 1, 1, Random(0L), issuedBy = (DUMMY_CASH_ISSUER))
+            services.fillWithSomeTestCash(100.DOLLARS, DUMMY_NOTARY, 1, 1, Random(0L), issuedBy = (BOC.ref(1)), issuerKey = BOC_KEY, ref = OpaqueBytes.of(1))
+            services.fillWithSomeTestCash(100.DOLLARS, DUMMY_NOTARY, 1, 1, Random(0L), issuedBy = (BOC.ref(2)), issuerKey = BOC_KEY, ref = OpaqueBytes.of(2))
+            services.fillWithSomeTestCash(100.DOLLARS, DUMMY_NOTARY, 1, 1, Random(0L), issuedBy = (BOC.ref(3)), issuerKey = BOC_KEY, ref = OpaqueBytes.of(3))
+
+            val unconsumedStates = services.vaultService.unconsumedStates<Cash.State>().toList()
+            assertThat(unconsumedStates).hasSize(4)
+
+            val spendableStatesUSD = services.vaultService.unconsumedStatesForSpending<Cash.State>(200.DOLLARS, lockId = UUID.randomUUID(),
+                    onlyFromIssuerParties = setOf(BOC), withIssuerRefs = setOf(OpaqueBytes.of(1), OpaqueBytes.of(2))).toList()
+            assertThat(spendableStatesUSD).hasSize(2)
+            assertThat(spendableStatesUSD[0].state.data.amount.token.issuer.party).isEqualTo(BOC)
+            assertThat(spendableStatesUSD[0].state.data.amount.token.issuer.reference).isEqualTo(BOC.ref(1).reference)
+            assertThat(spendableStatesUSD[1].state.data.amount.token.issuer.reference).isEqualTo(BOC.ref(2).reference)
+        }
+    }
+
     @Test
     fun `unconsumedStatesForSpending insufficient amount`() {
         databaseTransaction(database) {