diff --git a/linkage_dag.py b/linkage_dag.py
index 3335d0d..8c17a6b 100644
--- a/linkage_dag.py
+++ b/linkage_dag.py
@@ -335,6 +335,12 @@
             destination_cloud_storage_uris=f"gs://{bucket}/{tmp_dir}/unlink/data*.jsonl",
             export_format="NEWLINE_DELIMITED_JSON",
         ),
+        BigQueryToGCSOperator(
+            task_id="export_ids_to_drop",
+            source_project_dataset_table=f"{staging_dataset}.ids_to_drop",
+            destination_cloud_storage_uris=f"gs://{bucket}/{tmp_dir}/ids_to_drop/data*.jsonl",
+            export_format="NEWLINE_DELIMITED_JSON",
+        ),
     ]
 
     # Start up godzilla of article linkage, update simhash indexes of title+abstract, run simhash, then create the
@@ -362,6 +368,7 @@
         f"/snap/bin/gsutil -m cp -r gs://{bucket}/{gcs_folder}/simhash_indexes .",
         f"/snap/bin/gsutil -m cp -r gs://{bucket}/{gcs_folder}/simhash_results .",
         f"/snap/bin/gsutil -m cp -r gs://{bucket}/{tmp_dir}/unlink .",
+        f"/snap/bin/gsutil -m cp -r gs://{bucket}/{tmp_dir}/ids_to_drop .",
         f"/snap/bin/gsutil -m cp -r gs://{bucket}/{tmp_dir}/prev_id_mapping .",
         "mkdir new_simhash_indexes",
     ]
diff --git a/sequences/merge_combined_metadata.tsv b/sequences/merge_combined_metadata.tsv
index f3a2d5f..1bec41c 100644
--- a/sequences/merge_combined_metadata.tsv
+++ b/sequences/merge_combined_metadata.tsv
@@ -3,3 +3,4 @@ metadata_match
 all_match_pairs_with_um
 simhash_input
 lid_input
+ids_to_drop
\ No newline at end of file
diff --git a/sql/ids_to_drop.sql b/sql/ids_to_drop.sql
new file mode 100644
index 0000000..235308e
--- /dev/null
+++ b/sql/ids_to_drop.sql
@@ -0,0 +1,6 @@
+select distinct
+    merged_id
+from
+    literature.sources
+where
+    orig_id in (select id1 from staging_literature.unlink)
\ No newline at end of file
diff --git a/tests/static/test_create_match_keys/ids_to_drop/data.jsonl b/tests/static/test_create_match_keys/ids_to_drop/data.jsonl
new file mode 100644
index 0000000..bae7d7e
--- /dev/null
+++ b/tests/static/test_create_match_keys/ids_to_drop/data.jsonl
@@ -0,0 +1 @@
+{"merged_id": "carticle_0000000003"}
\ No newline at end of file
diff --git a/tests/static/test_create_match_keys/input/input.jsonl b/tests/static/test_create_match_keys/input/input.jsonl
index bd95067..b2effcf 100644
--- a/tests/static/test_create_match_keys/input/input.jsonl
+++ b/tests/static/test_create_match_keys/input/input.jsonl
@@ -3,3 +3,5 @@
 {"orig_id": "D", "merged_id": "carticle_0000000002"}
 {"orig_id": "E", "merged_id": "carticle_0000000002"}
 {"orig_id": "F", "merged_id": "carticle_0000000001"}
+{"orig_id": "I", "merged_id": "carticle_0000000003"}
+{"orig_id": "J", "merged_id": "carticle_0000000003"}
\ No newline at end of file
diff --git a/tests/test_create_merge_ids.py b/tests/test_create_merge_ids.py
index ef6fefc..ee4b8cd 100644
--- a/tests/test_create_merge_ids.py
+++ b/tests/test_create_merge_ids.py
@@ -75,26 +75,32 @@ def test_skip_matches(self):
         )
 
     def test_create_match_keys(self):
-        # the first set will contain two old elts from the same match set and one new elt; should keep its id
-        # the next will contain one elt from one match set, two from another; should change ids
-        # the last will contain only new ids; should get a new id
-        match_sets = [{"A", "B", "C"}, {"D", "E", "F"}, {"G", "H"}]
+        # The first set (A, B, C) contains two old elts from the same match set and one new elt; should keep its id.
+        # The next (D, E, F) contains one elt from one match set, two from another; should change ids.
+        # Another (G, H) contains only new ids; should get a new id.
+        # The last two (I and J) are two different match sets that share an old id and are in ids_to_drop;
+        # each should get a new id (this is in case of unlinking).
+        match_sets = [{"A", "B", "C"}, {"D", "E", "F"}, {"G", "H"}, {"I"}, {"J"}]
         out_dir = os.path.join(static_dir, "test_create_match_keys", "output")
         if os.path.exists(out_dir):
             shutil.rmtree(out_dir)
         os.mkdir(out_dir)
         out_fi = os.path.join(out_dir, "output.jsonl")
         id_mapping_dir = os.path.join(static_dir, "test_create_match_keys", "input")
+        ids_to_drop = os.path.join(static_dir, "test_create_match_keys", "ids_to_drop")
         expected_output = [
             {"orig_id": "A", "merged_id": "carticle_0000000001"},
             {"orig_id": "B", "merged_id": "carticle_0000000001"},
             {"orig_id": "C", "merged_id": "carticle_0000000001"},
-            {"orig_id": "D", "merged_id": "carticle_0000000003"},
-            {"orig_id": "E", "merged_id": "carticle_0000000003"},
-            {"orig_id": "F", "merged_id": "carticle_0000000003"},
-            {"orig_id": "G", "merged_id": "carticle_0000000004"},
-            {"orig_id": "H", "merged_id": "carticle_0000000004"},
+            {"orig_id": "D", "merged_id": "carticle_0000000004"},
+            {"orig_id": "E", "merged_id": "carticle_0000000004"},
+            {"orig_id": "F", "merged_id": "carticle_0000000004"},
+            {"orig_id": "G", "merged_id": "carticle_0000000005"},
+            {"orig_id": "H", "merged_id": "carticle_0000000005"},
+            {"orig_id": "I", "merged_id": "carticle_0000000006"},
+            {"orig_id": "J", "merged_id": "carticle_0000000007"},
         ]
-        create_match_keys(match_sets, out_fi, id_mapping_dir)
+        print(expected_output)
+        create_match_keys(match_sets, out_fi, ids_to_drop, id_mapping_dir)
         out = [json.loads(x) for x in open(out_fi).readlines()]
         self.assertEqual(expected_output, sorted(out, key=lambda x: x["orig_id"]))
diff --git a/utils/create_merge_ids.py b/utils/create_merge_ids.py
index 77c2dc6..1680873 100644
--- a/utils/create_merge_ids.py
+++ b/utils/create_merge_ids.py
@@ -128,13 +128,14 @@ def create_match_sets(
 
 
 def create_match_keys(
-    match_sets: list, match_file: str, prev_id_mapping_dir: str = None
+    match_sets: list, match_file: str, ids_to_drop: str, prev_id_mapping_dir: str = None
 ):
     """
     Given a match set, creates an id for that match set, and writes out a jsonl mapping each article in the match
     set to that id
     :param match_sets: list of match sets
     :param match_file: file where id mapping should be written
+    :param ids_to_drop: directory containing merged ids that should not be used in jsonl form
     :param prev_id_mapping_dir: optional dir containing previous id mappings in jsonl form
     :return: None
     """
@@ -152,6 +153,12 @@ def create_match_keys(
                         prev_orig_to_merg[orig_id] = merg_id
                         if merg_id > max_merg:
                             max_merg = merg_id
+        ignore_ids = set()
+        for fi in os.listdir(ids_to_drop):
+            with open(os.path.join(ids_to_drop, fi)) as f:
+                for line in f:
+                    js = json.loads(line.strip())
+                    ignore_ids.add(js["merged_id"])
         match_id = int(max_merg.split("carticle_")[1]) + 1
         num_new, num_old = 0, 0
         for ms in match_sets:
@@ -162,7 +169,7 @@ def create_match_keys(
             existing_ids = set(
                 [prev_orig_to_merg[m] for m in ms if m in prev_orig_to_merg]
             )
-            if len(existing_ids) == 1:
+            if len(existing_ids) == 1 and list(existing_ids)[0] not in ignore_ids:
                 cset_article_id = existing_ids.pop()
                 num_old += 1
             else:
@@ -189,6 +196,11 @@ def create_match_keys(
         required=True,
         help="directory of article pairs that should not be matched",
     )
+    parser.add_argument(
+        "--ids_to_drop",
+        required=True,
+        help="file containing ids that should not be used",
+    )
     parser.add_argument(
         "--merge_file", required=True, help="file where merged ids should be written"
     )
@@ -209,4 +221,4 @@ def create_match_keys(
     match_sets = create_match_sets(
         args.match_dir, args.current_ids_dir, args.exclude_dir
     )
-    create_match_keys(match_sets, args.merge_file, args.prev_id_mapping_dir)
+    create_match_keys(match_sets, args.merge_file, args.ids_to_drop, args.prev_id_mapping_dir)
diff --git a/utils/run_ids_scripts.sh b/utils/run_ids_scripts.sh
index 0660c5c..59a0db8 100644
--- a/utils/run_ids_scripts.sh
+++ b/utils/run_ids_scripts.sh
@@ -1,6 +1,6 @@
 cd /mnt/disks/data/run
 gsutil rm gs://airflow-data-exchange/article_linkage/tmp/done_files/ids_are_done
-python3 create_merge_ids.py --match_dir usable_ids --exclude_dir unlink --prev_id_mapping_dir prev_id_mapping --merge_file id_mapping.jsonl --current_ids_dir article_pairs
+python3 create_merge_ids.py --match_dir usable_ids --exclude_dir unlink --ids_to_drop ids_to_drop --prev_id_mapping_dir prev_id_mapping --merge_file id_mapping.jsonl --current_ids_dir article_pairs
 /snap/bin/gsutil -m cp id_mapping.jsonl gs://airflow-data-exchange/article_linkage/tmp/
 /snap/bin/gsutil -m cp simhash_results/* gs://airflow-data-exchange/article_linkage/simhash_results/
 /snap/bin/gsutil -m cp new_simhash_indexes/* gs://airflow-data-exchange/article_linkage/simhash_indexes/