diff --git a/src/open_inwoner/cms/cases/views/cases.py b/src/open_inwoner/cms/cases/views/cases.py
index 6321d21a2d..4c8f3d686d 100644
--- a/src/open_inwoner/cms/cases/views/cases.py
+++ b/src/open_inwoner/cms/cases/views/cases.py
@@ -14,9 +14,8 @@
 from zgw_consumers.concurrent import parallel
 
 from open_inwoner.htmx.mixins import RequiresHtmxMixin
-from open_inwoner.openzaak.api_models import Zaak
+from open_inwoner.openzaak.api_models import OpenSubmission, Zaak
 from open_inwoner.openzaak.cases import preprocess_data
-from open_inwoner.openzaak.formapi import fetch_open_submissions
 from open_inwoner.openzaak.models import OpenZaakConfig, ZGWApiGroupConfig
 from open_inwoner.openzaak.types import UniformCase
 from open_inwoner.openzaak.utils import get_user_fetch_parameters
@@ -47,17 +46,37 @@ def process_data(self) -> dict:
         return {**self.zaak.process_data(), "api_group": self.api_group}
 
 
+@dataclass(frozen=True)
+class SubmissionWithApiGroup:
+    submission: OpenSubmission
+    api_group: ZGWApiGroupConfig
+
+    @property
+    def identifier(self):
+        return self.submission.url
+
+    def process_data(self) -> dict:
+        return {**self.submission.process_data(), "api_group": self.api_group}
+
+
 class CaseListService:
     def __init__(self, request: HttpRequest):
         self.request = request
 
-    def get_cases_for_api_group(self, group: ZGWApiGroupConfig):
+    def get_cases_for_api_group(self, group: ZGWApiGroupConfig) -> list[UniformCase]:
         raw_cases = group.zaken_client.fetch_cases(
-            **get_user_fetch_parameters(self.request)
+            **get_user_fetch_parameters(self.request, check_rsin=True)
         )
         preprocessed_cases = preprocess_data(raw_cases, group)
         return preprocessed_cases
 
+    def get_submissions_for_api_group(
+        self, group: ZGWApiGroupConfig
+    ) -> list[UniformCase]:
+        return group.forms_client.fetch_open_submissions(
+            **get_user_fetch_parameters(self.request, check_rsin=False)
+        )
+
     def get_cases(self) -> list[ZaakWithApiGroup]:
         all_api_groups = list(ZGWApiGroupConfig.objects.all())
 
@@ -84,10 +103,35 @@ def get_cases(self) -> list[ZaakWithApiGroup]:
         return cases_with_api_group
 
     def get_submissions(self):
-        subs = fetch_open_submissions(self.request.user.bsn)
-        subs.sort(key=lambda sub: sub.datum_laatste_wijziging, reverse=True)
+        all_api_groups = list(
+            ZGWApiGroupConfig.objects.exclude(form_service__isnull=True)
+        )
+
+        with parallel() as executor:
+            futures = [
+                executor.submit(self.get_submissions_for_api_group, group)
+                for group in all_api_groups
+            ]
+
+            subs_with_api_group = []
+            for task in concurrent.futures.as_completed(futures):
+                try:
+                    group_for_task = all_api_groups[futures.index(task)]
+                    for row in task.result():
+                        subs_with_api_group.append(
+                            SubmissionWithApiGroup(
+                                submission=row, api_group=group_for_task
+                            )
+                        )
+                except BaseException:
+                    logger.exception("Error fetching and pre-processing cases")
+
+        # Sort submissions by date modified
+        subs_with_api_group.sort(
+            key=lambda sub: sub.submission.datum_laatste_wijziging, reverse=True
+        )
 
-        return subs
+        return subs_with_api_group
 
     @staticmethod
     def get_case_filter_status(zaak: Zaak) -> CaseFilterFormOption:
diff --git a/src/open_inwoner/openzaak/clients.py b/src/open_inwoner/openzaak/clients.py
index 35497a126b..b727826c6b 100644
--- a/src/open_inwoner/openzaak/clients.py
+++ b/src/open_inwoner/openzaak/clients.py
@@ -63,21 +63,25 @@ class ZakenClient(ZgwAPIClient):
     def fetch_cases(
         self,
         user_bsn: str | None = None,
-        user_kvk_or_rsin: str | None = None,
+        user_kvk: str | None = None,
+        user_rsin: str | None = None,
         max_requests: int = 4,
         identificatie: str | None = None,
         vestigingsnummer: str | None = None,
     ):
-        if user_bsn and (user_kvk_or_rsin or vestigingsnummer):
+        if user_bsn and (user_kvk or user_rsin or vestigingsnummer):
             raise ValueError(
-                "either `user_bsn` or `user_kvk_or_rsin`/`vestigingsnummer` should be supplied, not both"
+                "either `user_bsn` or `user_kvk`/`user_risin` (+ optionally `vestigingsnummer`) "
+                "should be supplied, not both"
             )
 
         if user_bsn:
             return self.fetch_cases_by_bsn(
                 user_bsn, max_requests=max_requests, identificatie=identificatie
             )
-        elif user_kvk_or_rsin:
+
+        if user_kvk or user_rsin:
+            user_kvk_or_rsin = user_rsin if user_rsin else user_kvk
             return self.fetch_cases_by_kvk_or_rsin(
                 user_kvk_or_rsin,
                 max_requests=max_requests,
@@ -666,17 +670,71 @@ def upload_document(
 
 
 class FormClient(ZgwAPIClient):
-    def fetch_open_submissions(self, bsn: str) -> list[OpenSubmission]:
-        if not bsn:
+    def fetch_open_submissions(
+        self,
+        user_bsn: str | None = None,
+        user_kvk: str | None = None,
+        vestigingsnummer: str | None = None,
+        max_requests: int = 4,
+        **kwargs,
+    ):
+        if user_bsn and (user_kvk or vestigingsnummer):
+            raise ValueError(
+                "either `user_bsn` or `user_kvk` (optionally with `vestigingsnummer`) "
+                "should be supplied, not both"
+            )
+
+        if user_bsn:
+            return self.fetch_open_submissions_by_bsn(
+                user_bsn, max_requests=max_requests
+            )
+
+        if user_kvk:
+            return self.fetch_open_submissions_by_kvk(
+                user_kvk,
+                max_requests=max_requests,
+                vestigingsnummer=vestigingsnummer,
+            )
+
+        return []
+
+    def fetch_open_submissions_by_bsn(
+        self,
+        user_bsn: str,
+        max_requests: int,
+    ) -> list[OpenSubmission]:
+        try:
+            response = self.get(
+                "openstaande-inzendingen",
+                params={"bsn": user_bsn},
+            )
+            data = get_json_response(response)
+            all_data = list(pagination_helper(self, data, max_requests=max_requests))
+        except (RequestException, ClientError) as e:
+            logger.exception("exception while making request", exc_info=e)
             return []
 
+        results = factory(OpenSubmission, all_data)
+
+        return results
+
+    def fetch_open_submissions_by_kvk(
+        self,
+        user_kvk: str,
+        vestigingsnummer: str | None,
+        max_requests: int,
+    ) -> list[OpenSubmission]:
+        request_params = {"kvk": user_kvk}
+        if vestigingsnummer:
+            request_params["vestigingsnummer"] = vestigingsnummer
+
         try:
             response = self.get(
                 "openstaande-inzendingen",
-                params={"bsn": bsn},
+                params=request_params,
             )
             data = get_json_response(response)
-            all_data = list(pagination_helper(self, data))
+            all_data = list(pagination_helper(self, data, max_requests=max_requests))
         except (RequestException, ClientError) as e:
             logger.exception("exception while making request", exc_info=e)
             return []
diff --git a/src/open_inwoner/openzaak/formapi.py b/src/open_inwoner/openzaak/formapi.py
deleted file mode 100644
index 4be12469cb..0000000000
--- a/src/open_inwoner/openzaak/formapi.py
+++ /dev/null
@@ -1,16 +0,0 @@
-import logging
-
-from open_inwoner.openzaak.clients import build_forms_client
-
-from .api_models import OpenSubmission
-
-logger = logging.getLogger(__name__)
-
-
-def fetch_open_submissions(bsn: str) -> list[OpenSubmission]:
-    client = build_forms_client()
-
-    if client is None:
-        return []
-
-    return client.fetch_open_submissions(bsn)
diff --git a/src/open_inwoner/openzaak/tests/mocks.py b/src/open_inwoner/openzaak/tests/mocks.py
index f4fecdee94..4cddacfa77 100644
--- a/src/open_inwoner/openzaak/tests/mocks.py
+++ b/src/open_inwoner/openzaak/tests/mocks.py
@@ -1,8 +1,17 @@
+from furl import furl
+from zgw_consumers.api_models.constants import VertrouwelijkheidsAanduidingen
+
+from open_inwoner.accounts.models import User
 from open_inwoner.openzaak.tests.shared import FORMS_ROOT
+from open_inwoner.utils.test import paginated_response
 
 
 class ESuiteSubmissionData:
-    def __init__(self):
+    def __init__(self, *, zaken_root: str, forms_root: str, user: User):
+        self.zaken_root = zaken_root
+        self.forms_root = forms_root
+        self.user = user
+
         self.submission_1 = {
             "url": "https://dmidoffice2.esuite-development.net/formulieren-provider/api/v1/8e3ae29c-7bc5-4f7d-a27c-b0c83c13328e",
             "uuid": "8e3ae29c-7bc5-4f7d-a27c-b0c83c13328e",
@@ -19,18 +28,64 @@ def __init__(self):
             "datumLaatsteWijziging": "2023-02-13T14:10:26.197000+0100",
             "eindDatumGeldigheid": "2023-05-14T14:10:26.197+02:00",
         }
-        # note this is a weird esuite response without pagination links
-        self.response = {
-            "count": 2,
-            "results": [
-                self.submission_1,
-                self.submission_2,
-            ],
+        self.submission_3 = {
+            "url": "https://dmidoffice2.esuite-development.net/formulieren-provider/api/v1/e25769c1-dcb4-4d3c-a61c-fd7d0c78f296",
+            "uuid": "e25769c1-dcb4-4d3c-a61c-fd7d0c78f296",
+            "naam": "Indienen bezwaarschrift",
+            "vervolgLink": "https://dloket2.esuite-development.net/formulieren-nieuw/formulier/start/e25769c1-dcb4-4d3c-a61c-fd7d0c78f296",
+            "datumLaatsteWijziging": "2023-04-05T14:10:26.197000+0100",
+            "eindDatumGeldigheid": "2023-06-14T14:10:26.197+02:00",
         }
 
-    def install_mocks(self, m):
+        # esuite response without pagination links
+        if self.forms_root == FORMS_ROOT:
+            self.response = {
+                "count": 2,
+                "results": [
+                    self.submission_1,
+                    self.submission_2,
+                ],
+            }
+        else:
+            self.response = {
+                "count": 1,
+                "results": [
+                    self.submission_3,
+                ],
+            }
+
+    def install_digid_mocks(self, m):
+        m.get(
+            furl(f"{self.zaken_root}zaken")
+            .add(
+                {
+                    "rol__betrokkeneIdentificatie__natuurlijkPersoon__inpBsn": self.user.bsn,
+                    "maximaleVertrouwelijkheidaanduiding": VertrouwelijkheidsAanduidingen.openbaar,
+                }
+            )
+            .url,
+            json=paginated_response([]),
+        )
+        m.get(
+            f"{self.forms_root}openstaande-inzendingen",
+            json=self.response,
+        )
+        return self
+
+    def install_eherkenning_mocks(self, m):
+        m.get(
+            furl(f"{self.zaken_root}zaken")
+            .add(
+                {
+                    "rol__betrokkeneIdentificatie__nietNatuurlijkPersoon__innNnpId": self.user.kvk,
+                    "maximaleVertrouwelijkheidaanduiding": VertrouwelijkheidsAanduidingen.openbaar,
+                }
+            )
+            .url,
+            json=paginated_response([]),
+        )
         m.get(
-            f"{FORMS_ROOT}openstaande-inzendingen",
+            f"{self.forms_root}openstaande-inzendingen",
             json=self.response,
         )
         return self
diff --git a/src/open_inwoner/openzaak/tests/test_cases.py b/src/open_inwoner/openzaak/tests/test_cases.py
index 936fa28d67..3328bbcc35 100644
--- a/src/open_inwoner/openzaak/tests/test_cases.py
+++ b/src/open_inwoner/openzaak/tests/test_cases.py
@@ -21,7 +21,6 @@
 from open_inwoner.accounts.choices import LoginTypeChoices
 from open_inwoner.accounts.tests.factories import UserFactory, eHerkenningUserFactory
 from open_inwoner.cms.cases.views.cases import CaseFilterFormOption, InnerCaseListView
-from open_inwoner.openzaak.tests.shared import FORMS_ROOT
 from open_inwoner.utils.test import (
     ClearCachesMixin,
     paginated_response,
@@ -41,7 +40,14 @@
 )
 from .helpers import generate_oas_component_cached
 from .mocks import ESuiteSubmissionData
-from .shared import ANOTHER_CATALOGI_ROOT, ANOTHER_ZAKEN_ROOT, CATALOGI_ROOT, ZAKEN_ROOT
+from .shared import (
+    ANOTHER_CATALOGI_ROOT,
+    ANOTHER_FORMS_ROOT,
+    ANOTHER_ZAKEN_ROOT,
+    CATALOGI_ROOT,
+    FORMS_ROOT,
+    ZAKEN_ROOT,
+)
 
 
 class SeededUUIDGenerator:
@@ -1103,25 +1109,62 @@ def setUp(self):
             zrc_service__api_root=ZAKEN_ROOT,
             form_service__api_root=FORMS_ROOT,
         )
+        ZGWApiGroupConfigFactory(
+            zrc_service__api_root=ANOTHER_ZAKEN_ROOT,
+            form_service__api_root=ANOTHER_FORMS_ROOT,
+        )
 
     @requests_mock.Mocker()
-    def test_case_submission(self, m):
-        user = UserFactory(
+    def test_get_open_submissions_by_bsn(self, m):
+        digid_user = UserFactory(
             login_type=LoginTypeChoices.digid, bsn="900222086", email="john@smith.nl"
         )
-        m.get(
-            furl(f"{ZAKEN_ROOT}zaken")
-            .add(
-                {
-                    "rol__betrokkeneIdentificatie__natuurlijkPersoon__inpBsn": user.bsn,
-                    "maximaleVertrouwelijkheidaanduiding": VertrouwelijkheidsAanduidingen.openbaar,
-                }
-            )
-            .url,
-            json=paginated_response([]),
+        data = ESuiteSubmissionData(
+            zaken_root=ZAKEN_ROOT, forms_root=FORMS_ROOT, user=digid_user
+        ).install_digid_mocks(m)
+        data_alt = ESuiteSubmissionData(
+            zaken_root=ANOTHER_ZAKEN_ROOT,
+            forms_root=ANOTHER_FORMS_ROOT,
+            user=digid_user,
+        ).install_digid_mocks(m)
+
+        response = self.app.get(
+            self.inner_url, user=digid_user, headers={"HX-Request": "true"}
+        )
+
+        cases = response.context["cases"]
+
+        self.assertEqual(len(cases), 3)
+
+        # submission cases are sorted in reverse by `last modified`
+        self.assertEqual(cases[0]["url"], data_alt.submission_3["url"])
+        self.assertEqual(cases[0]["uuid"], data_alt.submission_3["uuid"])
+        self.assertEqual(cases[0]["naam"], data_alt.submission_3["naam"])
+        self.assertEqual(cases[0]["vervolg_link"], data_alt.submission_3["vervolgLink"])
+        self.assertEqual(
+            cases[0]["datum_laatste_wijziging"].strftime("%Y-%m-%dT%H:%M:%S.%f%z"),
+            data_alt.submission_3["datumLaatsteWijziging"],
+        )
+
+        self.assertEqual(cases[1]["url"], data.submission_2["url"])
+        self.assertEqual(cases[1]["uuid"], data.submission_2["uuid"])
+        self.assertEqual(cases[1]["naam"], data.submission_2["naam"])
+        self.assertEqual(cases[1]["vervolg_link"], data.submission_2["vervolgLink"])
+        self.assertEqual(
+            cases[1]["datum_laatste_wijziging"].strftime("%Y-%m-%dT%H:%M:%S.%f%z"),
+            data.submission_2["datumLaatsteWijziging"],
         )
 
-        data = ESuiteSubmissionData().install_mocks(m)
+    @requests_mock.Mocker()
+    @patch("open_inwoner.kvk.middleware.kvk_branch_selected_done")
+    def test_get_open_submissions_by_kvk(self, m, kvk_branch_selected):
+        user = UserFactory(login_type=LoginTypeChoices.eherkenning, kvk="68750110")
+        data = ESuiteSubmissionData(
+            zaken_root=ZAKEN_ROOT, forms_root=FORMS_ROOT, user=user
+        ).install_eherkenning_mocks(m)
+        data_alt = ESuiteSubmissionData(
+            zaken_root=ANOTHER_ZAKEN_ROOT, forms_root=ANOTHER_FORMS_ROOT, user=user
+        ).install_eherkenning_mocks(m)
 
         response = self.app.get(
             self.inner_url, user=user, headers={"HX-Request": "true"}
@@ -1129,14 +1172,23 @@ def test_case_submission(self, m):
 
         cases = response.context["cases"]
 
-        self.assertEqual(len(cases), 2)
+        self.assertEqual(len(cases), 3)
 
         # submission cases are sorted in reverse by `last modified`
-        self.assertEqual(cases[0]["url"], data.submission_2["url"])
-        self.assertEqual(cases[0]["uuid"], data.submission_2["uuid"])
-        self.assertEqual(cases[0]["naam"], data.submission_2["naam"])
-        self.assertEqual(cases[0]["vervolg_link"], data.submission_2["vervolgLink"])
+        self.assertEqual(cases[0]["url"], data_alt.submission_3["url"])
+        self.assertEqual(cases[0]["uuid"], data_alt.submission_3["uuid"])
+        self.assertEqual(cases[0]["naam"], data_alt.submission_3["naam"])
+        self.assertEqual(cases[0]["vervolg_link"], data_alt.submission_3["vervolgLink"])
         self.assertEqual(
             cases[0]["datum_laatste_wijziging"].strftime("%Y-%m-%dT%H:%M:%S.%f%z"),
+            data_alt.submission_3["datumLaatsteWijziging"],
+        )
+
+        self.assertEqual(cases[1]["url"], data.submission_2["url"])
+        self.assertEqual(cases[1]["uuid"], data.submission_2["uuid"])
+        self.assertEqual(cases[1]["naam"], data.submission_2["naam"])
+        self.assertEqual(cases[1]["vervolg_link"], data.submission_2["vervolgLink"])
+        self.assertEqual(
+            cases[1]["datum_laatste_wijziging"].strftime("%Y-%m-%dT%H:%M:%S.%f%z"),
             data.submission_2["datumLaatsteWijziging"],
         )
diff --git a/src/open_inwoner/openzaak/utils.py b/src/open_inwoner/openzaak/utils.py
index 9c484572d5..e798fb11b6 100644
--- a/src/open_inwoner/openzaak/utils.py
+++ b/src/open_inwoner/openzaak/utils.py
@@ -126,7 +126,7 @@ def get_zaak_type_info_object_type_config(
         return None
 
 
-def get_user_fetch_parameters(request) -> dict:
+def get_user_fetch_parameters(request, check_rsin: bool = True) -> dict:
     """
     Determine the parameters used to perform ZGW resource fetches
     """
@@ -137,15 +137,19 @@ def get_user_fetch_parameters(request) -> dict:
 
     if user.bsn:
         return {"user_bsn": user.bsn}
-    elif user.kvk:
-        kvk_or_rsin = user.kvk
-        config = OpenZaakConfig.get_solo()
-        if config.fetch_eherkenning_zaken_with_rsin:
-            kvk_or_rsin = user.rsin
 
-        parameters = {"user_kvk_or_rsin": kvk_or_rsin}
+    if user.kvk:
+        parameters = {"user_kvk": user.kvk}
+
+        if check_rsin:
+            config = OpenZaakConfig.get_solo()
+            if config.fetch_eherkenning_zaken_with_rsin:
+                parameters = {"user_rsin": user.rsin}
+
         vestigingsnummer = get_kvk_branch_number(request.session)
         if vestigingsnummer:
             parameters.update({"vestigingsnummer": vestigingsnummer})
+
         return parameters
+
     return {}