diff --git a/node/src/main/kotlin/net/corda/node/services/schema/NodeSchemaService.kt b/node/src/main/kotlin/net/corda/node/services/schema/NodeSchemaService.kt
index 1133e33042..c4e27a4ff8 100644
--- a/node/src/main/kotlin/net/corda/node/services/schema/NodeSchemaService.kt
+++ b/node/src/main/kotlin/net/corda/node/services/schema/NodeSchemaService.kt
@@ -56,7 +56,10 @@ class NodeSchemaService(private val extraSchemas: Set<MappedSchema> = emptySet()
                   Pair(NodeCoreV1, SchemaOptions()))
 
     fun internalSchemas() = requiredSchemas.keys + extraSchemas.filter { schema -> // when mapped schemas from the finance module are present, they are considered as internal ones
-        schema::class.qualifiedName == "net.corda.finance.schemas.CashSchemaV1" || schema::class.qualifiedName == "net.corda.finance.schemas.CommercialPaperSchemaV1" }
+        schema::class.qualifiedName == "net.corda.finance.schemas.CashSchemaV1" ||
+                schema::class.qualifiedName == "net.corda.finance.schemas.CommercialPaperSchemaV1" ||
+                schema::class.qualifiedName == "net.corda.node.services.transactions.NodeNotarySchemaV1"
+    }
 
     override val schemaOptions: Map<MappedSchema, SchemaService.SchemaOptions> = requiredSchemas + extraSchemas.associateBy({ it }, { SchemaOptions() })
 
diff --git a/node/src/main/kotlin/net/corda/node/services/transactions/PersistentUniquenessProvider.kt b/node/src/main/kotlin/net/corda/node/services/transactions/PersistentUniquenessProvider.kt
index 9b82d98e89..4c71feb333 100644
--- a/node/src/main/kotlin/net/corda/node/services/transactions/PersistentUniquenessProvider.kt
+++ b/node/src/main/kotlin/net/corda/node/services/transactions/PersistentUniquenessProvider.kt
@@ -70,6 +70,14 @@ class PersistentUniquenessProvider(val clock: Clock, val database: CordaPersiste
             var requestDate: Instant
     )
 
+    @Entity
+    @javax.persistence.Table(name = "${NODE_DATABASE_PREFIX}notary_committed_transactions")
+    class CommittedTransaction(
+            @Id
+            @Column(name = "transaction_id", nullable = false, length = 64)
+            val transactionId: String
+    )
+
     private data class CommitRequest(
             val states: List<StateRef>,
             val txId: SecureHash,
@@ -190,13 +198,32 @@ class PersistentUniquenessProvider(val clock: Clock, val database: CordaPersiste
             logRequest(txId, callerIdentity, requestSignature)
             val conflictingStates = findAlreadyCommitted(states, references, commitLog)
             if (conflictingStates.isNotEmpty()) {
-                handleConflicts(txId, conflictingStates)
+                if (states.isEmpty()) {
+                    handleReferenceConflicts(txId, conflictingStates)
+                } else {
+                    handleConflicts(txId, conflictingStates)
+                }
             } else {
                 handleNoConflicts(timeWindow, states, txId, commitLog)
             }
         }
     }
 
+    private fun previouslyCommitted(txId: SecureHash): Boolean {
+        val session = currentDBSession()
+        return session.find(CommittedTransaction::class.java, txId.toString()) != null
+    }
+
+    private fun handleReferenceConflicts(txId: SecureHash, conflictingStates: LinkedHashMap<StateRef, StateConsumptionDetails>) {
+        val session = currentDBSession()
+        if (!previouslyCommitted(txId)) {
+            val conflictError = NotaryError.Conflict(txId, conflictingStates)
+            log.debug { "Failure, input states already committed: ${conflictingStates.keys}" }
+            throw NotaryInternalException(conflictError)
+        }
+        log.debug { "Transaction $txId already notarised" }
+    }
+
     private fun handleConflicts(txId: SecureHash, conflictingStates: LinkedHashMap<StateRef, StateConsumptionDetails>) {
         if (isConsumedByTheSameTx(txId.sha256(), conflictingStates)) {
             log.debug { "Transaction $txId already notarised" }
@@ -214,8 +241,13 @@ class PersistentUniquenessProvider(val clock: Clock, val database: CordaPersiste
             states.forEach { stateRef ->
                 commitLog[stateRef] = txId
             }
+            val session = currentDBSession()
+            session.persist(CommittedTransaction(txId.toString()))
             log.debug { "Successfully committed all input states: $states" }
         } else {
+            if (states.isEmpty() && previouslyCommitted(txId)) {
+                return
+            }
             throw NotaryInternalException(outsideTimeWindowError)
         }
     }
diff --git a/node/src/main/kotlin/net/corda/node/services/transactions/SimpleNotaryService.kt b/node/src/main/kotlin/net/corda/node/services/transactions/SimpleNotaryService.kt
index 8efcbdc930..713aa27747 100644
--- a/node/src/main/kotlin/net/corda/node/services/transactions/SimpleNotaryService.kt
+++ b/node/src/main/kotlin/net/corda/node/services/transactions/SimpleNotaryService.kt
@@ -34,7 +34,8 @@ object NodeNotarySchema
 object NodeNotarySchemaV1 : MappedSchema(schemaFamily = NodeNotarySchema.javaClass, version = 1,
         mappedTypes = listOf(PersistentUniquenessProvider.BaseComittedState::class.java,
                 PersistentUniquenessProvider.Request::class.java,
-                PersistentUniquenessProvider.CommittedState::class.java
+                PersistentUniquenessProvider.CommittedState::class.java,
+                PersistentUniquenessProvider.CommittedTransaction::class.java
         )) {
     override val migrationResource = "node-notary.changelog-master"
-}
\ No newline at end of file
+}
diff --git a/node/src/main/resources/migration/node-notary.changelog-committed-transactions-table.xml b/node/src/main/resources/migration/node-notary.changelog-committed-transactions-table.xml
new file mode 100644
index 0000000000..0c2bfc6939
--- /dev/null
+++ b/node/src/main/resources/migration/node-notary.changelog-committed-transactions-table.xml
@@ -0,0 +1,14 @@
+<?xml version="1.1" encoding="UTF-8" standalone="no"?>
+<databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
+                   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+                   xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-3.5.xsd">
+
+    <changeSet author="R3.Corda" id="create-notary-committed-transactions-table">
+        <createTable tableName="node_notary_committed_transactions">
+            <column name="transaction_id" type="NVARCHAR(64)">
+                <constraints nullable="false"/>
+            </column>
+        </createTable>
+        <addPrimaryKey columnNames="transaction_id" constraintName="node_notary_transactions_pkey" tableName="node_notary_committed_transactions"/>
+    </changeSet>
+</databaseChangeLog>
diff --git a/node/src/main/resources/migration/node-notary.changelog-master.xml b/node/src/main/resources/migration/node-notary.changelog-master.xml
index 9f169670fc..6ebd2c54ce 100644
--- a/node/src/main/resources/migration/node-notary.changelog-master.xml
+++ b/node/src/main/resources/migration/node-notary.changelog-master.xml
@@ -8,5 +8,6 @@
 
     <include file="migration/node-notary.changelog-v1.xml"/>
     <include file="migration/node-notary.changelog-pkey.xml"/>
+    <include file="migration/node-notary.changelog-committed-transactions-table.xml" />
 
 </databaseChangeLog>
diff --git a/node/src/test/kotlin/net/corda/node/services/transactions/PersistentUniquenessProviderTests.kt b/node/src/test/kotlin/net/corda/node/services/transactions/PersistentUniquenessProviderTests.kt
index 540991b887..544fa78fa7 100644
--- a/node/src/test/kotlin/net/corda/node/services/transactions/PersistentUniquenessProviderTests.kt
+++ b/node/src/test/kotlin/net/corda/node/services/transactions/PersistentUniquenessProviderTests.kt
@@ -1,14 +1,16 @@
 package net.corda.node.services.transactions
 
+import net.corda.core.contracts.TimeWindow
 import net.corda.core.crypto.DigitalSignature
 import net.corda.core.crypto.NullKeys
 import net.corda.core.crypto.SecureHash
 import net.corda.core.crypto.sha256
 import net.corda.core.flows.NotarisationRequestSignature
 import net.corda.core.flows.NotaryError
+import net.corda.core.flows.StateConsumptionDetails
 import net.corda.core.identity.CordaX500Name
-import net.corda.core.internal.notary.NotaryInternalException
 import net.corda.core.internal.notary.UniquenessProvider
+import net.corda.core.utilities.minutes
 import net.corda.node.services.schema.NodeSchemaService
 import net.corda.nodeapi.internal.persistence.CordaPersistence
 import net.corda.nodeapi.internal.persistence.DatabaseConfig
@@ -19,13 +21,14 @@ import net.corda.testing.internal.LogHelper
 import net.corda.testing.internal.TestingNamedCacheFactory
 import net.corda.testing.internal.configureDatabase
 import net.corda.testing.node.MockServices.Companion.makeTestDataSourceProperties
+import net.corda.testing.node.TestClock
 import org.junit.After
 import org.junit.Before
 import org.junit.Rule
 import org.junit.Test
 import java.time.Clock
 import kotlin.test.assertEquals
-import kotlin.test.assertFailsWith
+import kotlin.test.assertTrue
 
 class PersistentUniquenessProviderTests {
     @Rule
@@ -70,10 +73,98 @@ class PersistentUniquenessProviderTests {
 
         val secondTxId = SecureHash.randomSHA256()
 
-        val response:UniquenessProvider.Result  = provider.commit(inputs, secondTxId, identity, requestSignature).get()
+        val response: UniquenessProvider.Result  = provider.commit(inputs, secondTxId, identity, requestSignature).get()
         val error = (response as UniquenessProvider.Result.Failure).error as NotaryError.Conflict
 
         val conflictCause = error.consumedStates[inputState]!!
+        assertEquals(firstTxId.sha256(), conflictCause.hashOfTransactionId)
+    }
+
+    @Test
+    fun `rejects transaction with invalid time window`() {
+        val provider = PersistentUniquenessProvider(Clock.systemUTC(), database, TestingNamedCacheFactory())
+        val inputState1 = generateStateRef()
+        val firstTxId = SecureHash.randomSHA256()
+        val timeWindow = TimeWindow.fromOnly(Clock.systemUTC().instant().plus(30.minutes))
+        val result = provider.commit(listOf(inputState1), firstTxId, identity, requestSignature, timeWindow).get()
+        val error = (result as UniquenessProvider.Result.Failure).error as NotaryError.TimeWindowInvalid
+        assertEquals(timeWindow, error.txTimeWindow)
+    }
+
+    @Test
+    fun `handles transaction with valid time window`() {
+        val provider = PersistentUniquenessProvider(Clock.systemUTC(), database, TestingNamedCacheFactory())
+        val inputState1 = generateStateRef()
+        val firstTxId = SecureHash.randomSHA256()
+        val timeWindow = TimeWindow.untilOnly(Clock.systemUTC().instant().plus(30.minutes))
+        val result = provider.commit(listOf(inputState1), firstTxId, identity, requestSignature, timeWindow).get()
+        assertEquals(UniquenessProvider.Result.Success, result)
+    }
+
+    @Test
+    fun `handles transaction with valid time window without inputs`() {
+        val testClock = TestClock(Clock.systemUTC())
+        val provider = PersistentUniquenessProvider(testClock, database, TestingNamedCacheFactory())
+        val firstTxId = SecureHash.randomSHA256()
+        val timeWindow = TimeWindow.untilOnly(Clock.systemUTC().instant().plus(30.minutes))
+        val result = provider.commit(emptyList(), firstTxId, identity, requestSignature, timeWindow).get()
+        assertEquals(UniquenessProvider.Result.Success, result)
+
+        // Re-notarisation works outside the specified time window.
+        testClock.advanceBy(90.minutes)
+        val result2 = provider.commit(emptyList(), firstTxId, identity, requestSignature, timeWindow).get()
+        assertEquals(UniquenessProvider.Result.Success, result2)
+    }
+
+    @Test
+    fun `handles reference states`() {
+        val provider = PersistentUniquenessProvider(Clock.systemUTC(), database, TestingNamedCacheFactory())
+        val inputState1 = generateStateRef()
+        val inputState2 = generateStateRef()
+        val firstTxId = SecureHash.randomSHA256()
+        val secondTxId = SecureHash.randomSHA256()
+
+        // Conflict free transaction goes through.
+        val result1 = provider.commit(listOf(inputState1), firstTxId, identity, requestSignature, references = listOf(inputState2)).get()
+        assertEquals(UniquenessProvider.Result.Success, result1)
+
+        // Referencing a spent state results in a conflict.
+        val result2 = provider.commit(listOf(inputState2), secondTxId, identity, requestSignature, references = listOf(inputState1)).get()
+        val error = (result2 as UniquenessProvider.Result.Failure).error as NotaryError.Conflict
+        val conflictCause = error.consumedStates[inputState1]!!
         assertEquals(conflictCause.hashOfTransactionId, firstTxId.sha256())
+        assertEquals(StateConsumptionDetails.ConsumedStateType.REFERENCE_INPUT_STATE, conflictCause.type)
+
+        // Re-notarisation works.
+        val result3 = provider.commit(listOf(inputState1), firstTxId, identity, requestSignature, references = listOf(inputState2)).get()
+        assertEquals(UniquenessProvider.Result.Success, result3)
+    }
+
+    @Test
+    fun `handles transaction with reference states only`() {
+        val provider = PersistentUniquenessProvider(Clock.systemUTC(), database, TestingNamedCacheFactory())
+        val inputState1 = generateStateRef()
+        val firstTxId = SecureHash.randomSHA256()
+        val secondTxId = SecureHash.randomSHA256()
+        val thirdTxId = SecureHash.randomSHA256()
+
+        // Conflict free transaction goes through.
+        val result1 = provider.commit(emptyList(), firstTxId, identity, requestSignature, references = listOf(inputState1)).get()
+        assertEquals(UniquenessProvider.Result.Success, result1)
+
+        // Commit state 1.
+        val result2 = provider.commit(listOf(inputState1), secondTxId, identity, requestSignature).get()
+        assertEquals(UniquenessProvider.Result.Success, result2)
+
+        // Re-notarisation works.
+        val result3 = provider.commit(emptyList(), firstTxId, identity, requestSignature, references = listOf(inputState1)).get()
+        assertEquals(UniquenessProvider.Result.Success, result3)
+
+        // Transaction referencing the spent sate fails.
+        val result4 = provider.commit(emptyList(), thirdTxId, identity, requestSignature, references = listOf(inputState1)).get()
+        val error = (result4 as UniquenessProvider.Result.Failure).error as NotaryError.Conflict
+        val conflictCause = error.consumedStates[inputState1]!!
+        assertEquals(conflictCause.hashOfTransactionId, secondTxId.sha256())
+        assertEquals(StateConsumptionDetails.ConsumedStateType.REFERENCE_INPUT_STATE, conflictCause.type)
     }
 }