diff --git a/qa/rpc-tests/wallet_sapling.py b/qa/rpc-tests/wallet_sapling.py
index 1aecba5d3..1abb1e8dc 100755
--- a/qa/rpc-tests/wallet_sapling.py
+++ b/qa/rpc-tests/wallet_sapling.py
@@ -19,17 +19,57 @@ class WalletSaplingTest(BitcoinTestFramework):
     def setup_nodes(self):
         return start_nodes(4, self.options.tmpdir, [[
             '-nuparams=5ba81b19:201', # Overwinter
-            '-nuparams=76b809bb:201', # Sapling
+            '-nuparams=76b809bb:203', # Sapling
+            '-experimentalfeatures', '-zmergetoaddress',
         ]] * 4)
 
     def run_test(self):
         # Sanity-check the test harness
         assert_equal(self.nodes[0].getblockcount(), 200)
 
-        # Activate Sapling
+        # Activate Overwinter
         self.nodes[2].generate(1)
         self.sync_all()
 
+        # Verify RPCs disallow Sapling value transfer if Sapling is not active
+        tmp_taddr = self.nodes[3].getnewaddress()
+        tmp_zaddr = self.nodes[3].z_getnewaddress('sapling')
+        try:
+            recipients = []
+            recipients.append({"address": tmp_zaddr, "amount": Decimal('20')})
+            self.nodes[3].z_sendmany(tmp_taddr, recipients, 1, 0)
+            raise AssertionError("Should have thrown an exception")
+        except JSONRPCException as e:
+            assert_equal("Invalid parameter, Sapling has not activated", e.error['message'])
+        try:
+            recipients = []
+            recipients.append({"address": tmp_taddr, "amount": Decimal('20')})
+            self.nodes[3].z_sendmany(tmp_zaddr, recipients, 1, 0)
+            raise AssertionError("Should have thrown an exception")
+        except JSONRPCException as e:
+            assert_equal("Invalid parameter, Sapling has not activated", e.error['message'])
+        try:
+            self.nodes[3].z_shieldcoinbase(tmp_taddr, tmp_zaddr)
+            raise AssertionError("Should have thrown an exception")
+        except JSONRPCException as e:
+            assert_equal("Invalid parameter, Sapling has not activated", e.error['message'])
+
+        # Verify z_mergetoaddress RPC does not support Sapling yet
+        try:
+            self.nodes[3].z_mergetoaddress([tmp_taddr], tmp_zaddr)
+            raise AssertionError("Should have thrown an exception")
+        except JSONRPCException as e:
+            assert_equal("Invalid parameter, Sapling is not supported yet by z_mergetoadress", e.error['message'])
+        try:
+            self.nodes[3].z_mergetoaddress([tmp_zaddr], tmp_taddr)
+            raise AssertionError("Should have thrown an exception")
+        except JSONRPCException as e:
+            assert_equal("Invalid parameter, Sapling is not supported yet by z_mergetoadress", e.error['message'])
+
+        # Activate Sapling
+        self.nodes[2].generate(2)
+        self.sync_all()
+
         taddr0 = self.nodes[0].getnewaddress()
         # Skip over the address containing node 1's coinbase
         self.nodes[1].getnewaddress()
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 4bbf6271c..d6940aeb7 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -3795,6 +3795,13 @@ UniValue z_sendmany(const UniValue& params, bool fHelp)
         }
     }
 
+    // If Sapling is not active, do not allow sending from or sending to Sapling addresses.
+    if (!NetworkUpgradeActive(nextBlockHeight, Params().GetConsensus(), Consensus::UPGRADE_SAPLING)) {
+        if (fromSapling || containsSaplingOutput) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, Sapling has not activated");
+        }
+    }
+
     // As a sanity check, estimate and verify that the size of the transaction will be valid.
     // Depending on the input notes, the actual tx size may turn out to be larger and perhaps invalid.
     size_t txsize = 0;
@@ -3984,6 +3991,19 @@ UniValue z_shieldcoinbase(const UniValue& params, bool fHelp)
         max_tx_size = MAX_TX_SIZE_BEFORE_SAPLING;
     }
 
+    // If Sapling is not active, do not allow sending to a Sapling address.
+    if (!NetworkUpgradeActive(nextBlockHeight, Params().GetConsensus(), Consensus::UPGRADE_SAPLING)) {
+        auto res = DecodePaymentAddress(destaddress);
+        if (IsValidPaymentAddress(res)) {
+            bool toSapling = boost::get<libzcash::SaplingPaymentAddress>(&res) != nullptr;
+            if (toSapling) {
+                throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, Sapling has not activated");
+            }
+        } else {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, string("Invalid parameter, unknown address format: ") + destaddress );
+        }
+    }
+
     // Prepare to get coinbase utxos
     std::vector<ShieldCoinbaseUTXO> inputs;
     CAmount shieldedValue = 0;
@@ -4184,6 +4204,7 @@ UniValue z_mergetoaddress(const UniValue& params, bool fHelp)
     std::set<std::string> setAddress;
 
     // Sources
+    bool containsSaplingZaddrSource = false;
     for (const UniValue& o : addresses.getValues()) {
         if (!o.isStr())
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, expected string");
@@ -4209,6 +4230,9 @@ UniValue z_mergetoaddress(const UniValue& params, bool fHelp)
                     if (!(useAny || useAnyNote)) {
                         zaddrs.insert(zaddr);
                     }
+                    // Check if z-addr is Sapling
+                    bool isSapling = boost::get<libzcash::SaplingPaymentAddress>(&zaddr) != nullptr;
+                    containsSaplingZaddrSource |= isSapling;
                 } else {
                     throw JSONRPCError(
                         RPC_INVALID_PARAMETER,
@@ -4225,10 +4249,19 @@ UniValue z_mergetoaddress(const UniValue& params, bool fHelp)
     // Validate the destination address
     auto destaddress = params[1].get_str();
     bool isToZaddr = false;
+    bool isToSaplingZaddr = false;
     CTxDestination taddr = DecodeDestination(destaddress);
     if (!IsValidDestination(taddr)) {
         if (IsValidPaymentAddressString(destaddress)) {
             isToZaddr = true;
+
+            // Is this a Sapling address?
+            auto res = DecodePaymentAddress(destaddress);
+            if (IsValidPaymentAddress(res)) {
+                isToSaplingZaddr = boost::get<libzcash::SaplingPaymentAddress>(&res) != nullptr;
+            } else {
+                throw JSONRPCError(RPC_INVALID_PARAMETER, string("Invalid parameter, unknown address format: ") + destaddress );
+            }
         } else {
             throw JSONRPCError(RPC_INVALID_PARAMETER, string("Invalid parameter, unknown address format: ") + destaddress );
         }
@@ -4282,6 +4315,19 @@ UniValue z_mergetoaddress(const UniValue& params, bool fHelp)
         max_tx_size = MAX_TX_SIZE_BEFORE_SAPLING;
     }
 
+    // This RPC does not support Sapling yet.
+    if (isToSaplingZaddr || containsSaplingZaddrSource) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, Sapling is not supported yet by z_mergetoadress");
+    }
+
+    // If this RPC does support Sapling...
+    // If Sapling is not active, do not allow sending from or sending to Sapling addresses.
+    if (!NetworkUpgradeActive(nextBlockHeight, Params().GetConsensus(), Consensus::UPGRADE_SAPLING)) {
+        if (isToSaplingZaddr || containsSaplingZaddrSource) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, Sapling has not activated");
+        }
+    }
+
     // Prepare to get UTXOs and notes
     std::vector<MergeToAddressInputUTXO> utxoInputs;
     std::vector<MergeToAddressInputNote> noteInputs;