diff --git a/changelog.d/1-api-changes/mls-replace-kps b/changelog.d/1-api-changes/mls-replace-kps
new file mode 100644
index 00000000000..671b7d4b8c0
--- /dev/null
+++ b/changelog.d/1-api-changes/mls-replace-kps
@@ -0,0 +1 @@
+New endpoint for replacing MLS key packages in bulk: `PUT /mls/key-packages/self/:client`. It replaces all existing key packages that match the given ciphersuites with the new key packages provided in the body.
diff --git a/integration/test/API/Brig.hs b/integration/test/API/Brig.hs
index 455ce04e9d9..8e1c390862a 100644
--- a/integration/test/API/Brig.hs
+++ b/integration/test/API/Brig.hs
@@ -302,6 +302,16 @@ deleteKeyPackages cid kps = do
   req <- baseRequest cid Brig Versioned ("/mls/key-packages/self/" <> cid.client)
   submit "DELETE" $ req & addJSONObject ["key_packages" .= kps]
 
+replaceKeyPackages :: ClientIdentity -> [Ciphersuite] -> [ByteString] -> App Response
+replaceKeyPackages cid suites kps = do
+  req <-
+    baseRequest cid Brig Versioned $
+      "/mls/key-packages/self/" <> cid.client
+  submit "PUT" $
+    req
+      & addQueryParams [("ciphersuites", intercalate "," (map (.code) suites))]
+      & addJSONObject ["key_packages" .= map (T.decodeUtf8 . Base64.encode) kps]
+
 getSelf :: HasCallStack => String -> String -> App Response
 getSelf domain uid = do
   let user = object ["domain" .= domain, "id" .= uid]
diff --git a/integration/test/MLS/Util.hs b/integration/test/MLS/Util.hs
index d6bef3fc8a0..94c2d520f21 100644
--- a/integration/test/MLS/Util.hs
+++ b/integration/test/MLS/Util.hs
@@ -174,7 +174,8 @@ createMLSClient opts u = do
 -- | create and upload to backend
 uploadNewKeyPackage :: HasCallStack => ClientIdentity -> App String
 uploadNewKeyPackage cid = do
-  (kp, ref) <- generateKeyPackage cid
+  mls <- getMLSState
+  (kp, ref) <- generateKeyPackage cid mls.ciphersuite
 
   -- upload key package
   bindResponse (uploadKeyPackages cid [kp]) $ \resp ->
@@ -182,10 +183,9 @@ uploadNewKeyPackage cid = do
 
   pure ref
 
-generateKeyPackage :: HasCallStack => ClientIdentity -> App (ByteString, String)
-generateKeyPackage cid = do
-  mls <- getMLSState
-  kp <- mlscli cid ["key-package", "create", "--ciphersuite", mls.ciphersuite.code] Nothing
+generateKeyPackage :: HasCallStack => ClientIdentity -> Ciphersuite -> App (ByteString, String)
+generateKeyPackage cid suite = do
+  kp <- mlscli cid ["key-package", "create", "--ciphersuite", suite.code] Nothing
   ref <- B8.unpack . Base64.encode <$> mlscli cid ["key-package", "ref", "-"] (Just kp)
   fp <- keyPackageFile cid ref
   liftIO $ BS.writeFile fp kp
diff --git a/integration/test/Test/MLS/KeyPackage.hs b/integration/test/Test/MLS/KeyPackage.hs
index 8f6cf9d20d3..78c7e87e0b5 100644
--- a/integration/test/Test/MLS/KeyPackage.hs
+++ b/integration/test/Test/MLS/KeyPackage.hs
@@ -56,10 +56,8 @@ testKeyPackageCount cs = do
     resp.status `shouldMatchInt` 200
     resp.json %. "count" `shouldMatchInt` 0
 
-  setMLSCiphersuite cs
-
   let count = 10
-  kps <- map fst <$> replicateM count (generateKeyPackage alice1)
+  kps <- map fst <$> replicateM count (generateKeyPackage alice1 cs)
   void $ uploadKeyPackages alice1 kps >>= getBody 201
 
   bindResponse (countKeyPackages cs alice1) $ \resp -> do
@@ -68,10 +66,79 @@ testKeyPackageCount cs = do
 
 testUnsupportedCiphersuite :: HasCallStack => App ()
 testUnsupportedCiphersuite = do
-  setMLSCiphersuite (Ciphersuite "0x0002")
+  let suite = Ciphersuite "0x0002"
+  setMLSCiphersuite suite
   bob <- randomUser OwnDomain def
   bob1 <- createMLSClient def bob
-  (kp, _) <- generateKeyPackage bob1
+  (kp, _) <- generateKeyPackage bob1 suite
   bindResponse (uploadKeyPackages bob1 [kp]) $ \resp -> do
     resp.status `shouldMatchInt` 400
     resp.json %. "label" `shouldMatch` "mls-protocol-error"
+
+testReplaceKeyPackages :: HasCallStack => App ()
+testReplaceKeyPackages = do
+  alice <- randomUser OwnDomain def
+  [alice1, alice2] <- replicateM 2 $ createMLSClient def alice
+  let suite = Ciphersuite "0xf031"
+
+  let checkCount cs n =
+        bindResponse (countKeyPackages cs alice1) $ \resp -> do
+          resp.status `shouldMatchInt` 200
+          resp.json %. "count" `shouldMatchInt` n
+
+  -- setup: upload a batch of key packages for each ciphersuite
+  void $
+    replicateM 4 (fmap fst (generateKeyPackage alice1 def))
+      >>= uploadKeyPackages alice1
+      >>= getBody 201
+  setMLSCiphersuite suite
+  void $
+    replicateM 5 (fmap fst (generateKeyPackage alice1 suite))
+      >>= uploadKeyPackages alice1
+      >>= getBody 201
+
+  checkCount def 4
+  checkCount suite 5
+
+  do
+    -- generate a new batch of key packages
+    (kps, refs) <- unzip <$> replicateM 3 (generateKeyPackage alice1 suite)
+
+    -- replace old key packages with new
+    void $ replaceKeyPackages alice1 [suite] kps >>= getBody 201
+
+    checkCount def 4
+    checkCount suite 3
+
+    -- claim all key packages one by one
+    claimed <-
+      replicateM 3 $
+        bindResponse (claimKeyPackages suite alice2 alice) $ \resp -> do
+          resp.status `shouldMatchInt` 200
+          ks <- resp.json %. "key_packages" & asList
+          k <- assertOne ks
+          k %. "key_package_ref"
+
+    refs `shouldMatchSet` claimed
+
+    checkCount def 4
+    checkCount suite 0
+
+  do
+    -- replenish key packages for the second ciphersuite
+    void $
+      replicateM 5 (fmap fst (generateKeyPackage alice1 suite))
+        >>= uploadKeyPackages alice1
+        >>= getBody 201
+
+    checkCount def 4
+    checkCount suite 5
+
+    -- replace all key packages with fresh ones
+    kps1 <- replicateM 2 (fmap fst (generateKeyPackage alice1 def))
+    kps2 <- replicateM 2 (fmap fst (generateKeyPackage alice1 suite))
+
+    void $ replaceKeyPackages alice1 [def, suite] (kps1 <> kps2) >>= getBody 201
+
+    checkCount def 2
+    checkCount suite 2
diff --git a/libs/wire-api/src/Wire/API/MLS/CipherSuite.hs b/libs/wire-api/src/Wire/API/MLS/CipherSuite.hs
index 1f358b58e61..7c51932a439 100644
--- a/libs/wire-api/src/Wire/API/MLS/CipherSuite.hs
+++ b/libs/wire-api/src/Wire/API/MLS/CipherSuite.hs
@@ -42,6 +42,7 @@ module Wire.API.MLS.CipherSuite
 where
 
 import Cassandra.CQL
+import Control.Applicative
 import Control.Error (note)
 import Control.Lens ((?~))
 import Crypto.Error
@@ -51,18 +52,20 @@ import Crypto.PubKey.Ed25519 qualified as Ed25519
 import Data.Aeson qualified as Aeson
 import Data.Aeson.Types (FromJSON (..), FromJSONKey (..), ToJSON (..), ToJSONKey (..))
 import Data.Aeson.Types qualified as Aeson
+import Data.Attoparsec.ByteString.Char8 qualified as Atto
 import Data.Bifunctor
 import Data.ByteArray hiding (index)
 import Data.ByteArray qualified as BA
+import Data.ByteString.Conversion
 import Data.OpenApi qualified as S
 import Data.OpenApi.Internal.Schema qualified as S
 import Data.Proxy
 import Data.Schema
 import Data.Text qualified as T
+import Data.Text.Encoding qualified as T
 import Data.Text.Lazy qualified as LT
 import Data.Text.Lazy.Builder qualified as LT
 import Data.Text.Lazy.Builder.Int qualified as LT
-import Data.Text.Read qualified as T
 import Data.Word
 import Imports hiding (cs)
 import Web.HttpApiData
@@ -85,11 +88,8 @@ instance S.ToParamSchema CipherSuite where
       & S.type_ ?~ S.OpenApiNumber
 
 instance FromHttpApiData CipherSuite where
-  parseUrlPiece t = do
-    (x, rest) <- first T.pack $ T.hexadecimal t
-    unless (T.null rest) $
-      Left "Trailing characters after ciphersuite number"
-    pure (CipherSuite x)
+  parseUrlPiece = parseHeader . T.encodeUtf8
+  parseHeader = first T.pack . runParser parser
 
 instance ToHttpApiData CipherSuite where
   toUrlPiece =
@@ -99,6 +99,11 @@ instance ToHttpApiData CipherSuite where
       . LT.hexadecimal
       . cipherSuiteNumber
 
+instance FromByteString CipherSuite where
+  parser = do
+    void $ Atto.try (optional (Atto.string "0x"))
+    CipherSuite <$> Atto.hexadecimal
+
 data CipherSuiteTag
   = MLS_128_DHKEMX25519_AES128GCM_SHA256_Ed25519
   | MLS_128_X25519Kyber768Draft00_AES128GCM_SHA256_Ed25519
diff --git a/libs/wire-api/src/Wire/API/MLS/KeyPackage.hs b/libs/wire-api/src/Wire/API/MLS/KeyPackage.hs
index 1402ff17b9a..da2855013e8 100644
--- a/libs/wire-api/src/Wire/API/MLS/KeyPackage.hs
+++ b/libs/wire-api/src/Wire/API/MLS/KeyPackage.hs
@@ -62,7 +62,8 @@ import Wire.API.MLS.Serialisation
 import Wire.Arbitrary
 
 data KeyPackageUpload = KeyPackageUpload
-  {keyPackages :: [RawMLS KeyPackage]}
+  { keyPackages :: [RawMLS KeyPackage]
+  }
   deriving (FromJSON, ToJSON, S.ToSchema) via Schema KeyPackageUpload
 
 instance ToSchema KeyPackageUpload where
diff --git a/libs/wire-api/src/Wire/API/Routes/Public/Brig.hs b/libs/wire-api/src/Wire/API/Routes/Public/Brig.hs
index 6e780914b7c..8a09807bc5c 100644
--- a/libs/wire-api/src/Wire/API/Routes/Public/Brig.hs
+++ b/libs/wire-api/src/Wire/API/Routes/Public/Brig.hs
@@ -1186,6 +1186,15 @@ type CipherSuiteParam =
     "ciphersuite"
     CipherSuite
 
+type MultipleCipherSuitesParam =
+  QueryParam'
+    [ Optional,
+      Strict,
+      Description "Comma-separated list of ciphersuites in hex format (e.g. 0xf031) - default is 0x0001"
+    ]
+    "ciphersuites"
+    (CommaSeparatedList CipherSuite)
+
 type MLSKeyPackageAPI =
   "key-packages"
     :> ( Named
@@ -1201,6 +1210,20 @@ type MLSKeyPackageAPI =
                :> ReqBody '[JSON] KeyPackageUpload
                :> MultiVerb 'POST '[JSON, MLS] '[RespondEmpty 201 "Key packages uploaded"] ()
            )
+           :<|> Named
+                  "mls-key-packages-replace"
+                  ( "self"
+                      :> Summary "Upload a fresh batch of key packages and replace the old ones"
+                      :> From 'V5
+                      :> Description "The request body should be a json object containing a list of base64-encoded key packages. Use this sparingly."
+                      :> ZLocalUser
+                      :> CanThrow 'MLSProtocolError
+                      :> CanThrow 'MLSIdentityMismatch
+                      :> CaptureClientId "client"
+                      :> MultipleCipherSuitesParam
+                      :> ReqBody '[JSON] KeyPackageUpload
+                      :> MultiVerb 'PUT '[JSON, MLS] '[RespondEmpty 201 "Key packages replaced"] ()
+                  )
            :<|> Named
                   "mls-key-packages-claim"
                   ( "claim"
diff --git a/services/brig/src/Brig/API/MLS/CipherSuite.hs b/services/brig/src/Brig/API/MLS/CipherSuite.hs
index ec6b9756787..da8182c0a41 100644
--- a/services/brig/src/Brig/API/MLS/CipherSuite.hs
+++ b/services/brig/src/Brig/API/MLS/CipherSuite.hs
@@ -15,15 +15,22 @@
 -- You should have received a copy of the GNU Affero General Public License along
 -- with this program. If not, see <https://www.gnu.org/licenses/>.
 
-module Brig.API.MLS.CipherSuite (getCipherSuite) where
+module Brig.API.MLS.CipherSuite (getCipherSuite, getCipherSuites) where
 
 import Brig.API.Handler
 import Brig.API.MLS.KeyPackages.Validation
 import Imports
 import Wire.API.MLS.CipherSuite
 
+getOneCipherSuite :: CipherSuite -> Handler r CipherSuiteTag
+getOneCipherSuite s =
+  maybe
+    (mlsProtocolError "Unknown ciphersuite")
+    pure
+    (cipherSuiteTag s)
+
 getCipherSuite :: Maybe CipherSuite -> Handler r CipherSuiteTag
-getCipherSuite mSuite = case mSuite of
-  Nothing -> pure defCipherSuite
-  Just x ->
-    maybe (mlsProtocolError "Unknown ciphersuite") pure (cipherSuiteTag x)
+getCipherSuite = maybe (pure defCipherSuite) getOneCipherSuite
+
+getCipherSuites :: Maybe [CipherSuite] -> Handler r [CipherSuiteTag]
+getCipherSuites = maybe (pure [defCipherSuite]) (traverse getOneCipherSuite)
diff --git a/services/brig/src/Brig/API/MLS/KeyPackages.hs b/services/brig/src/Brig/API/MLS/KeyPackages.hs
index 4a3c244b356..35d1edba025 100644
--- a/services/brig/src/Brig/API/MLS/KeyPackages.hs
+++ b/services/brig/src/Brig/API/MLS/KeyPackages.hs
@@ -21,6 +21,7 @@ module Brig.API.MLS.KeyPackages
     claimLocalKeyPackages,
     countKeyPackages,
     deleteKeyPackages,
+    replaceKeyPackages,
   )
 where
 
@@ -37,6 +38,7 @@ import Brig.Federation.Client
 import Brig.IO.Intra
 import Control.Monad.Trans.Except
 import Control.Monad.Trans.Maybe
+import Data.CommaSeparatedList
 import Data.Id
 import Data.Qualified
 import Data.Set qualified as Set
@@ -157,3 +159,15 @@ deleteKeyPackages lusr c mSuite (unDeleteKeyPackages -> refs) = do
   assertMLSEnabled
   suite <- getCipherSuite mSuite
   lift $ wrapClient (Data.deleteKeyPackages (tUnqualified lusr) c suite refs)
+
+replaceKeyPackages ::
+  Local UserId ->
+  ClientId ->
+  Maybe (CommaSeparatedList CipherSuite) ->
+  KeyPackageUpload ->
+  Handler r ()
+replaceKeyPackages lusr c (fmap toList -> mSuites) upload = do
+  assertMLSEnabled
+  suites <- getCipherSuites mSuites
+  lift $ wrapClient (Data.deleteAllKeyPackages (tUnqualified lusr) c suites)
+  uploadKeyPackages lusr c upload
diff --git a/services/brig/src/Brig/API/Public.hs b/services/brig/src/Brig/API/Public.hs
index 2ce4307aecc..623792268ce 100644
--- a/services/brig/src/Brig/API/Public.hs
+++ b/services/brig/src/Brig/API/Public.hs
@@ -373,6 +373,7 @@ servantSitemap =
     mlsAPI :: ServerT MLSAPI (Handler r)
     mlsAPI =
       Named @"mls-key-packages-upload" uploadKeyPackages
+        :<|> Named @"mls-key-packages-replace" replaceKeyPackages
         :<|> Named @"mls-key-packages-claim" claimKeyPackages
         :<|> Named @"mls-key-packages-count" countKeyPackages
         :<|> Named @"mls-key-packages-delete" deleteKeyPackages
diff --git a/services/brig/src/Brig/Data/MLS/KeyPackage.hs b/services/brig/src/Brig/Data/MLS/KeyPackage.hs
index a03192f32e6..7aaccc4d16c 100644
--- a/services/brig/src/Brig/Data/MLS/KeyPackage.hs
+++ b/services/brig/src/Brig/Data/MLS/KeyPackage.hs
@@ -20,6 +20,7 @@ module Brig.Data.MLS.KeyPackage
     claimKeyPackage,
     countKeyPackages,
     deleteKeyPackages,
+    deleteAllKeyPackages,
   )
 where
 
@@ -37,6 +38,7 @@ import Data.Qualified
 import Data.Time.Clock
 import Data.Time.Clock.POSIX
 import Imports
+import UnliftIO.Async
 import Wire.API.MLS.CipherSuite
 import Wire.API.MLS.KeyPackage
 import Wire.API.MLS.LeafNode
@@ -142,6 +144,22 @@ deleteKeyPackages u c suite refs =
     deleteQuery :: PrepQuery W (UserId, ClientId, CipherSuiteTag, [KeyPackageRef]) ()
     deleteQuery = "DELETE FROM mls_key_packages WHERE user = ? AND client = ? AND cipher_suite = ? AND ref in ?"
 
+deleteAllKeyPackages ::
+  (MonadClient m, MonadUnliftIO m) =>
+  UserId ->
+  ClientId ->
+  [CipherSuiteTag] ->
+  m ()
+deleteAllKeyPackages u c suites =
+  pooledForConcurrentlyN_ 16 suites $ \suite ->
+    retry x5 $
+      write
+        deleteQuery
+        (params LocalQuorum (u, c, suite))
+  where
+    deleteQuery :: PrepQuery W (UserId, ClientId, CipherSuiteTag) ()
+    deleteQuery = "DELETE FROM mls_key_packages WHERE user = ? AND client = ? AND cipher_suite = ?"
+
 --------------------------------------------------------------------------------
 -- Utilities