diff --git a/internal/api/grpc/instance/v2/converter.go b/internal/api/grpc/instance/v2/converter.go
index 30abf90dbf4..753f28e8266 100644
--- a/internal/api/grpc/instance/v2/converter.go
+++ b/internal/api/grpc/instance/v2/converter.go
@@ -12,8 +12,8 @@ import (
 
 func InstancesToPb(instances []*query.Instance) []*instance.Instance {
 	list := []*instance.Instance{}
-	for i, instance := range instances {
-		list[i] = ToProtoObject(instance)
+	for _, instance := range instances {
+		list = append(list, ToProtoObject(instance))
 	}
 	return list
 }
@@ -88,12 +88,13 @@ func fieldNameToInstanceColumn(fieldName instance.FieldName) query.Column {
 }
 
 func instanceQueriesToModel(queries []*instance.Query) (_ []query.SearchQuery, err error) {
-	q := make([]query.SearchQuery, len(queries))
-	for i, query := range queries {
-		q[i], err = instanceQueryToModel(query)
+	q := []query.SearchQuery{}
+	for _, query := range queries {
+		model, err := instanceQueryToModel(query)
 		if err != nil {
 			return nil, err
 		}
+		q = append(q, model)
 	}
 	return q, nil
 }
diff --git a/internal/api/grpc/instance/v2/converter_test.go b/internal/api/grpc/instance/v2/converter_test.go
new file mode 100644
index 00000000000..0678ba64011
--- /dev/null
+++ b/internal/api/grpc/instance/v2/converter_test.go
@@ -0,0 +1,228 @@
+package instance
+
+import (
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/zitadel/zitadel/cmd/build"
+	"github.com/zitadel/zitadel/internal/config/systemdefaults"
+	"github.com/zitadel/zitadel/internal/query"
+	"github.com/zitadel/zitadel/internal/zerrors"
+	filter "github.com/zitadel/zitadel/pkg/grpc/filter/v2beta"
+	"github.com/zitadel/zitadel/pkg/grpc/instance/v2"
+	"github.com/zitadel/zitadel/pkg/grpc/object/v2"
+	"google.golang.org/protobuf/types/known/timestamppb"
+)
+
+func Test_InstancesToPb(t *testing.T) {
+	instances := []*query.Instance{
+		{
+			ID:   "instance1",
+			Name: "Instance One",
+			Domains: []*query.InstanceDomain{
+				{
+					Domain:       "example.com",
+					IsPrimary:    true,
+					IsGenerated:  false,
+					Sequence:     1,
+					CreationDate: time.Unix(123, 0),
+					ChangeDate:   time.Unix(124, 0),
+					InstanceID:   "instance1",
+				},
+			},
+			Sequence:     1,
+			CreationDate: time.Unix(123, 0),
+			ChangeDate:   time.Unix(124, 0),
+		},
+	}
+
+	want := []*instance.Instance{
+		{
+			Id:   "instance1",
+			Name: "Instance One",
+			Domains: []*instance.Domain{
+				{
+					Domain:    "example.com",
+					Primary:   true,
+					Generated: false,
+					Details: &object.Details{
+						Sequence:      1,
+						ChangeDate:    &timestamppb.Timestamp{Seconds: 124},
+						CreationDate:  &timestamppb.Timestamp{Seconds: 123},
+						ResourceOwner: "instance1",
+					},
+				},
+			},
+			Version: build.Version(),
+			Details: &object.Details{
+				Sequence:      1,
+				ChangeDate:    &timestamppb.Timestamp{Seconds: 124},
+				CreationDate:  &timestamppb.Timestamp{Seconds: 123},
+				ResourceOwner: "instance1",
+			},
+		},
+	}
+
+	got := InstancesToPb(instances)
+	assert.Equal(t, want, got)
+}
+
+func Test_ListInstancesRequestToModel(t *testing.T) {
+	t.Parallel()
+
+	searchInstanceByID, err := query.NewInstanceIDsListSearchQuery("instance1", "instance2")
+	require.Nil(t, err)
+
+	tt := []struct {
+		testName       string
+		inputRequest   *instance.ListInstancesRequest
+		maxQueryLimit  uint64
+		expectedResult *query.InstanceSearchQueries
+		expectedError  error
+	}{
+		{
+			testName:      "when query limit exceeds max query limit should return invalid argument error",
+			maxQueryLimit: 1,
+			inputRequest: &instance.ListInstancesRequest{
+				Pagination:    &filter.PaginationRequest{Limit: 10, Offset: 0, Asc: true},
+				SortingColumn: instance.FieldName_FIELD_NAME_ID,
+				Queries:       []*instance.Query{{Query: &instance.Query_IdQuery{IdQuery: &instance.IdsQuery{Ids: []string{"instance1", "instance2"}}}}},
+			},
+			expectedError: zerrors.ThrowInvalidArgumentf(errors.New("given: 10, allowed: 1"), "QUERY-4M0fs", "Errors.Query.LimitExceeded"),
+		},
+		{
+			testName: "when valid request should return instance search query model",
+			inputRequest: &instance.ListInstancesRequest{
+				Pagination:    &filter.PaginationRequest{Limit: 10, Offset: 0, Asc: true},
+				SortingColumn: instance.FieldName_FIELD_NAME_ID,
+				Queries:       []*instance.Query{{Query: &instance.Query_IdQuery{IdQuery: &instance.IdsQuery{Ids: []string{"instance1", "instance2"}}}}},
+			},
+			expectedResult: &query.InstanceSearchQueries{
+				SearchRequest: query.SearchRequest{
+					Offset:        0,
+					Limit:         10,
+					Asc:           true,
+					SortingColumn: query.InstanceColumnID,
+				},
+				Queries: []query.SearchQuery{searchInstanceByID},
+			},
+		},
+	}
+
+	for _, tc := range tt {
+		t.Run(tc.testName, func(t *testing.T) {
+			t.Parallel()
+			sysDefaults := systemdefaults.SystemDefaults{MaxQueryLimit: tc.maxQueryLimit}
+
+			got, err := ListInstancesRequestToModel(tc.inputRequest, sysDefaults)
+			assert.Equal(t, tc.expectedError, err)
+			assert.Equal(t, tc.expectedResult, got)
+
+		})
+	}
+}
+
+func Test_fieldNameToInstanceColumn(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name      string
+		fieldName instance.FieldName
+		want      query.Column
+	}{
+		{
+			name:      "ID field",
+			fieldName: instance.FieldName_FIELD_NAME_ID,
+			want:      query.InstanceColumnID,
+		},
+		{
+			name:      "Name field",
+			fieldName: instance.FieldName_FIELD_NAME_NAME,
+			want:      query.InstanceColumnName,
+		},
+		{
+			name:      "Creation Date field",
+			fieldName: instance.FieldName_FIELD_NAME_CREATION_DATE,
+			want:      query.InstanceColumnCreationDate,
+		},
+		{
+			name:      "Unknown field",
+			fieldName: instance.FieldName(99),
+			want:      query.Column{},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			got := fieldNameToInstanceColumn(tt.fieldName)
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
+
+func Test_instanceQueryToModel(t *testing.T) {
+	t.Parallel()
+
+	searchInstanceByID, err := query.NewInstanceIDsListSearchQuery("instance1")
+	require.Nil(t, err)
+
+	searchInstanceByDomain, err := query.NewInstanceDomainsListSearchQuery("example.com")
+	require.Nil(t, err)
+
+	tests := []struct {
+		name        string
+		searchQuery *instance.Query
+		want        query.SearchQuery
+		wantErr     bool
+	}{
+		{
+			name: "ID Query",
+			searchQuery: &instance.Query{
+				Query: &instance.Query_IdQuery{
+					IdQuery: &instance.IdsQuery{
+						Ids: []string{"instance1"},
+					},
+				},
+			},
+			want:    searchInstanceByID,
+			wantErr: false,
+		},
+		{
+			name: "Domain Query",
+			searchQuery: &instance.Query{
+				Query: &instance.Query_DomainQuery{
+					DomainQuery: &instance.DomainsQuery{
+						Domains: []string{"example.com"},
+					},
+				},
+			},
+			want:    searchInstanceByDomain,
+			wantErr: false,
+		},
+		{
+			name: "Invalid Query",
+			searchQuery: &instance.Query{
+				Query: nil,
+			},
+			want:    nil,
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			got, err := instanceQueryToModel(tt.searchQuery)
+			if tt.wantErr {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.want, got)
+			}
+		})
+	}
+}