diff --git a/src/Jobs/Handler/Print.hs b/src/Jobs/Handler/Print.hs
index 630a946eb..60ac7484b 100644
--- a/src/Jobs/Handler/Print.hs
+++ b/src/Jobs/Handler/Print.hs
@@ -18,34 +18,52 @@ import qualified Data.Text as Text
 
 -- import           Database.Persist.Sql (deleteWhereCount)
 -- import           Database.Esqueleto.Experimental ((:&)(..))
--- import qualified Database.Esqueleto.Experimental as E
--- import qualified Database.Esqueleto.Legacy as E
+import qualified Database.Esqueleto.Experimental as E
+import qualified Database.Esqueleto.Utils as E
 -- import qualified Database.Esqueleto.PostgreSQL as E -- for insertSelect variant
--- import qualified Database.Esqueleto.Utils as E
+-- import qualified Database.Esqueleto.Legacy as E
 
-
-jobPrintAckChunkSize :: Int 
+jobPrintAckChunkSize :: Int
 jobPrintAckChunkSize = 64
 
+-- | Maximum length difference between received and stored apcIdent
+--   APC sometimes sends ids back that are shorter than expected
+apcIdentMaxDiff :: Int
+apcIdentMaxDiff = 3
+
 -- needed, since JobPrintAck cannot requeue itself due to JobNoQueueSame (and having no parameters)
 dispatchJobPrintAckAgain :: JobHandler UniWorX
 dispatchJobPrintAckAgain = JobHandlerException act
-  where 
+  where
     act = void $ queueJob JobPrintAck
       -- liftIO $ threadDelay 3e6 -- wait 3s before continuing UPDATE: no wait needed
-      
+
 
 dispatchJobPrintAck :: JobHandler UniWorX
 dispatchJobPrintAck = JobHandlerException act
-  where    
+  where
     act = do
-      moretodo <- runDB $ do 
+      moretodo <- runDB $ do
         aliases <- selectList [] [Desc PrintAckIdAliasPriority]
         let ftransAliases = id : fmap (\Entity{entityVal=PrintAckIdAlias{printAckIdAliasNeedle=n, printAckIdAliasReplacement=r}} -> Text.replace n r) aliases
-            ackOneId ackt apci = selectKeysList [PrintJobApcIdent ==. apci, PrintJobAcknowledged ==. Nothing] [Asc PrintJobCreated, LimitTo 1] >>= \case
-                [pjid]  ->  update pjid [PrintJobAcknowledged =. Just ackt] >>
-                            return True
-                _       ->  return False
+            ackOneId ackt apci = selectKeysList [PrintJobApcIdent ==. apci, PrintJobAcknowledged ==. Nothing] [Asc PrintJobCreated, LimitTo 1] >>= \case -- mark oldest as done, if there are multiple with the same identifier
+                [pjid]  ->  update pjid [PrintJobAcknowledged =. Just ackt] $> True
+                _       ->  do
+                  pjcs <- E.select $ do
+                    let len_apci   = Text.length apci
+                        ifx_bounds = (E.val $  len_apci - apcIdentMaxDiff, E.val $ len_apci + apcIdentMaxDiff)
+                    pj <- E.from $ E.table @PrintJob
+                    E.where_ $ E.isNothing (pj E.^. PrintJobAcknowledged)
+                        E.&&. (E.length_ (pj E.^. PrintJobApcIdent) `E.between` ifx_bounds)
+                        E.&&. (E.isInfixOf (E.val apci) (pj E.^. PrintJobApcIdent)
+                         E.||. E.isInfixOf (pj E.^. PrintJobApcIdent) (E.val apci)
+                              )
+                    E.orderBy [E.asc $ pj E.^. PrintJobCreated] -- mark oldest printjob as done, if there are multiple matching jobs
+                    E.limit 1
+                    return $ pj E.^. PrintJobId
+                  case pjcs of
+                    [E.Value pjid] -> update pjid [PrintJobAcknowledged =. Just ackt] $> True
+                    _              -> return False
             procOneId oks Entity{entityKey=paid, entityVal=PrintAcknowledge{printAcknowledgeApcIdent=Text.strip -> apci, printAcknowledgeTimestamp=ackt}} =
                 orM [ackOneId ackt $ ftrans apci | ftrans <- ftransAliases] >>= \case
                   True  -> delete paid                                      >> return (succ oks)