diff --git a/src-executables/Main-trident.hs b/src-executables/Main-trident.hs
index 0727acc7..81c33f47 100644
--- a/src-executables/Main-trident.hs
+++ b/src-executables/Main-trident.hs
@@ -275,3 +275,6 @@ jannocoalesceOptParser = JannoCoalesceOptions <$> parseJannocoalSourceSpec
                                               <*> parseJannocoalOutSpec
                                               <*> parseJannocoalFillColumns
                                               <*> parseJannocoalOverride
+                                              <*> parseJannocoalSourceKey
+                                              <*> parseJannocoalTargetKey
+                                              <*> parseJannocoalIdStripRegex
diff --git a/src/Poseidon/CLI/Jannocoalesce.hs b/src/Poseidon/CLI/Jannocoalesce.hs
index 9fcfb7b0..55a454ad 100644
--- a/src/Poseidon/CLI/Jannocoalesce.hs
+++ b/src/Poseidon/CLI/Jannocoalesce.hs
@@ -10,14 +10,16 @@ import           Poseidon.Package       (PackageReadOptions (..),
 import           Poseidon.Utils         (PoseidonException (..), PoseidonIO,
                                          logInfo)
 
-import           Control.Monad          (forM)
+import           Control.Monad          (filterM, forM)
 import           Control.Monad.Catch    (MonadThrow, throwM)
 import           Control.Monad.IO.Class (liftIO)
 import qualified Data.ByteString.Char8  as BSC
 import qualified Data.Csv               as Csv
 import qualified Data.HashMap.Strict    as HM
+import           Data.List.Utils        (replace)
 import           System.Directory       (createDirectoryIfMissing)
 import           System.FilePath        (takeDirectory)
+import           Text.Regex.TDFA        (subRegex)
 
 -- the source can be a single janno file, or a set of base directories as usual.
 data JannoSourceSpec = JannoSourceSingle FilePath | JannoSourceBaseDirs [FilePath]
@@ -28,10 +30,13 @@ data JannoCoalesceOptions = JannoCoalesceOptions
     , _jannocoalesceOutSpec          :: Maybe FilePath -- Nothing means "in place"
     , _jannocoalesceFillColumns      :: [String] -- empty list means All
     , _jannocoalesceOverwriteColumns :: Bool
+    , _jannocoalesceSourceKey        :: String -- by default set to "Poseidon_ID"
+    , _jannocoalesceTargetKey        :: String -- by default set to "Poseidon_ID"
+    , _jannocoalesceIdStrip          :: Maybe String -- an optional regex to strip from target and source keys
     }
 
 runJannocoalesce :: JannoCoalesceOptions -> PoseidonIO ()
-runJannocoalesce (JannoCoalesceOptions sourceSpec target outSpec fields overwrite) = do
+runJannocoalesce (JannoCoalesceOptions sourceSpec target outSpec fields overwrite sKey tKey maybeStrip) = do
     JannoRows sourceRows <- case sourceSpec of
         JannoSourceSingle sourceFile -> readJannoFile sourceFile
         JannoSourceBaseDirs sourceDirs -> do
@@ -44,8 +49,8 @@ runJannocoalesce (JannoCoalesceOptions sourceSpec target outSpec fields overwrit
             getJointJanno <$> readPoseidonPackageCollection pacReadOpts sourceDirs
     JannoRows targetRows <- readJannoFile target
     newJanno <- forM targetRows $ \targetRow -> do
-        let posId = jPoseidonID targetRow
-            sourceRowCandidates = filter (\r -> jPoseidonID r == posId) sourceRows
+        posId <- getKeyFromJanno targetRow tKey
+        sourceRowCandidates <- filterM (\r -> (matchWithOptionalStrip maybeStrip posId) <$> getKeyFromJanno r sKey) sourceRows
         case sourceRowCandidates of
             [] -> return targetRow
             [keyRow] -> mergeRow targetRow keyRow fields overwrite
@@ -56,6 +61,26 @@ runJannocoalesce (JannoCoalesceOptions sourceSpec target outSpec fields overwrit
         createDirectoryIfMissing True (takeDirectory outPath)
         writeJannoFile outPath (JannoRows newJanno)
 
+getKeyFromJanno :: (MonadThrow m) => JannoRow -> String -> m String
+getKeyFromJanno jannoRow key = do
+    let jannoRowDict = Csv.toNamedRecord jannoRow
+    case jannoRowDict HM.!? (BSC.pack key) of
+        Nothing -> throwM $ PoseidonGenericException ("Key " ++ key ++ " not present in janno file")
+        Just r -> return $ BSC.unpack r
+
+matchWithOptionalStrip :: (Maybe String) -> String -> String -> Bool
+matchWithOptionalStrip maybeRegex id1 id2 =
+    case maybeRegex of
+        Nothing -> id1 == id2
+        Just r ->
+            let id1stripped = stripR (mkRegex r) id1 ""
+                id2stripped = stripR (mkRegex r) id2 ""
+            in  id1stripped == id2stripped
+  where
+    stripR r s =
+        let match = s =~ r
+        in  replace s match ""
+
 mergeRow :: (MonadThrow m) => JannoRow -> JannoRow -> [String] -> Bool -> m JannoRow
 mergeRow targetRow sourceRow fields overwrite = do
     let targetRowRecord = Csv.toNamedRecord targetRow
diff --git a/src/Poseidon/CLI/OptparseApplicativeParsers.hs b/src/Poseidon/CLI/OptparseApplicativeParsers.hs
index df1e5823..947621ec 100644
--- a/src/Poseidon/CLI/OptparseApplicativeParsers.hs
+++ b/src/Poseidon/CLI/OptparseApplicativeParsers.hs
@@ -807,3 +807,14 @@ parseJannocoalOverride = OP.switch (
     OP.short 'f' <>
     OP.help "With this option, potential non-missing content in target columns gets overridden with non-missing content in source columns. By default, only missing data gets filled-in."
     )
+
+parseJannocoalSourceKey :: OP.Parser String
+parseJannocoalSourceKey = OP.strOption (OP.long "sourceKey" <> OP.help "the janno column to use as the source key" <> OP.value "Poseidon_ID" <> OP.showDefault)
+
+parseJannocoalTargetKey :: OP.Parser String
+parseJannocoalTargetKey = OP.strOption (OP.long "targetKey" <> OP.help "the janno column to use as the target key" <> OP.value "Poseidon_ID" <> OP.showDefault)
+
+parseJannocoalIdStripRegex :: OP.Parser (Maybe String)
+parseJannocoalIdStripRegex = OP.option (Just <$> OP.str) (OP.long "stripIdSuffix" <>
+    OP.help "an optional regular expression to identify parts of the IDs to strip before matching between source and target" <> OP.value Nothing)
+
diff --git a/test/PoseidonGoldenTests/GoldenTestsRunCommands.hs b/test/PoseidonGoldenTests/GoldenTestsRunCommands.hs
index b10657e4..62b161be 100644
--- a/test/PoseidonGoldenTests/GoldenTestsRunCommands.hs
+++ b/test/PoseidonGoldenTests/GoldenTestsRunCommands.hs
@@ -1091,7 +1091,10 @@ testPipelineJannocoalesce testDir checkFilePath = do
             _jannocoalesceTarget           = "test/testDat/testJannoFiles/normal_subset.janno",
             _jannocoalesceOutSpec          = Just (testDir </> "jannocoalesce" </> "targetNoFieldsNoOverride.janno"),
             _jannocoalesceFillColumns      = [],
-            _jannocoalesceOverwriteColumns = False
+            _jannocoalesceOverwriteColumns = False,
+            _jannocoalesceSourceKey        = "Poseidon_ID",
+            _jannocoalesceTargetKey        = "Poseidon_ID",
+            _jannocoalesceIdStripRegex     = Nothing
         }
     runAndChecksumFiles checkFilePath testDir (testLog $ runJannocoalesce jannocoalesceOpts1) "jannocoalesce" [
           "jannocoalesce" </> "targetNoFieldsNoOverride.janno"