diff --git a/jmclient/jmclient/wallet-rpc-api.yaml b/jmclient/jmclient/wallet-rpc-api.yaml
index 00e0373..6e77e31 100644
--- a/jmclient/jmclient/wallet-rpc-api.yaml
+++ b/jmclient/jmclient/wallet-rpc-api.yaml
@@ -399,6 +399,31 @@ paths:
           $ref: "#/components/responses/401-Unauthorized"
         '409':
           $ref: '#/components/responses/409-NoConfig'
+  /wallet/{walletname}/freeze:
+    post:
+      security:
+        - bearerAuth: []
+      summary: freeze or unfreeze an individual utxo for spending
+      operationId: freeze
+      description: freeze or unfreeze an individual utxo for spending
+      parameters:
+        - name: walletname
+          in: path
+          description: name of wallet including .jmdat
+          required: true
+          schema:
+            type: string
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/FreezeRequest'
+        description: utxo string and freeze toggle as boolean
+      responses:
+        '200':
+          $ref: "#/components/responses/Freeze-200-OK"
+        '400':
+          $ref: '#/components/responses/400-BadRequest'
   /wallet/{walletname}/getseed:
     get:
       security:
@@ -432,6 +457,16 @@ components:
       scheme: bearer
       bearerFormat: JWT
   schemas:
+    FreezeRequest:
+      type: object
+      required:
+        - utxo-string
+        - freeze
+      properties:
+        utxo-string:
+          type: string
+        freeze:
+          type: boolean
     ConfigSetRequest:
       type: object
       required:
@@ -464,6 +499,8 @@ components:
           type: string
     ConfigSetResponse:
       type: object
+    FreezeResponse:
+      type: object
     DoCoinjoinRequest:
       type: object
       required:
@@ -830,6 +867,12 @@ components:
         application/json:
           schema:
             $ref: "#/components/schemas/GetSeedResponse"
+    Freeze-200-OK:
+      description: "freeze or unfreeze utxo action completed successfully"
+      content:
+        application/json:
+          schema:
+            $ref: "#/components/schemas/FreezeResponse"
     202-Accepted:
       description: The request has been submitted successfully for processing, but the processing has not been completed. 
     204-NoResultFound:
diff --git a/jmclient/jmclient/wallet_rpc.py b/jmclient/jmclient/wallet_rpc.py
index 5d82f4d..ce0c090 100644
--- a/jmclient/jmclient/wallet_rpc.py
+++ b/jmclient/jmclient/wallet_rpc.py
@@ -22,7 +22,7 @@ from jmclient import Taker, jm_single, \
     StorageError, StoragePasswordError, JmwalletdWebSocketServerFactory, \
     JmwalletdWebSocketServerProtocol, RetryableStorageError, \
     SegwitWalletFidelityBonds, wallet_gettimelockaddress
-from jmbase.support import get_log
+from jmbase.support import get_log, utxostr_to_utxo
 
 jlog = get_log()
 
@@ -791,6 +791,35 @@ class JMWalletDaemon(Service):
             # null return indicates success in updating:
             return make_jmwalletd_response(request)
 
+        @app.route('/wallet/<string:walletname>/freeze', methods=["POST"])
+        def freeze(self, request, walletname):
+            """ Freeze (true) or unfreeze (false), for spending a specified utxo
+            in this wallet. Note that this is persisted in the wallet file,
+            so the status survives across sessions. Note that re-application of
+            the same state is allowed and does not alter the 200 OK return.
+            """
+            self.check_cookie(request)
+            if not self.wallet_name == walletname:
+                raise InvalidRequestFormat()
+            freeze_json = self.get_POST_body(request, ["utxo-string", "freeze"])
+            if not freeze_json:
+                raise InvalidRequestFormat()
+            to_disable = freeze_json["freeze"]
+            valid, txidindex = utxostr_to_utxo(freeze_json["utxo-string"])
+            if not valid:
+                raise InvalidRequestFormat()
+            txid, index = txidindex
+            try:
+                # note: this does not raise or fail if the applied
+                # disable state (true/false) is the same as the current
+                # one; that is accepted and not an error.
+                self.wallet_service.disable_utxo(txid, index, to_disable)
+            except AssertionError:
+                # should be impossible because format checked by
+                # utxostr_to_utxo:
+                raise InvalidRequestFormat()
+            return make_jmwalletd_response(request)
+
         def get_listutxos_response(self, utxos):
             res = []
             for k, v in utxos.items():
diff --git a/jmclient/test/test_wallet_rpc.py b/jmclient/test/test_wallet_rpc.py
index 6e81ae0..5291012 100644
--- a/jmclient/test/test_wallet_rpc.py
+++ b/jmclient/test/test_wallet_rpc.py
@@ -381,16 +381,31 @@ class TrialTestWRPC_DisplayWallet(WalletRPCTestBase, unittest.TestCase):
         assert validate_address(json_body["address"])[0]
 
     @defer.inlineCallbacks
-    def test_listutxos(self):
+    def test_listutxos_and_freeze(self):
         self.daemon.auth_disabled = True
         agent = get_nontor_agent()
-        addr = self.get_route_root()
-        addr += "/wallet/"
-        addr += self.daemon.wallet_name
-        addr += "/utxos"
+        pre_addr = self.get_route_root()
+        pre_addr += "/wallet/"
+        pre_addr += self.daemon.wallet_name
+        addr = pre_addr + "/utxos"
         addr = addr.encode()
         yield self.do_request(agent, b"GET", addr, None,
                               self.process_listutxos_response)
+        # Test of freezing is currently very primitive: we only
+        # check that the action was accepted; a full test would
+        # involve checking that spending the coin works or doesn't
+        # work, as expected.
+        addr = pre_addr + "/freeze"
+        addr = addr.encode()
+        utxostr = self.mixdepth1_utxos[0]["utxo"]
+        body = BytesProducer(json.dumps({"utxo-string": utxostr,
+            "freeze": True}).encode())
+        yield self.do_request(agent, b"POST", addr, body,
+                              self.process_utxo_freeze)
+        body = BytesProducer(json.dumps({"utxo-string": utxostr,
+            "freeze": False}).encode())
+        yield self.do_request(agent, b"POST", addr, body,
+                              self.process_utxo_freeze)
 
     def process_listutxos_response(self, response, code):
         assert code == 200
@@ -399,11 +414,15 @@ class TrialTestWRPC_DisplayWallet(WalletRPCTestBase, unittest.TestCase):
         # have depend on what other tests occurred.
         # For now, we at least check that we have 3 utxos in mixdepth
         # 1 because none of the other tests spend them:
-        mixdepth1_utxos = 0
+        mixdepth1_utxos = []
         for d in json_body["utxos"]:
             if d["mixdepth"] == 1:
-                mixdepth1_utxos += 1
-        assert mixdepth1_utxos == 3
+                mixdepth1_utxos.append(d)
+        assert len(mixdepth1_utxos) == 3
+        self.mixdepth1_utxos = mixdepth1_utxos
+
+    def process_utxo_freeze(self, response, code):
+        assert code == 200
 
     @defer.inlineCallbacks
     def test_session(self):