diff --git a/Makefile b/Makefile
index f9898503aea..ea159b1ac96 100644
--- a/Makefile
+++ b/Makefile
@@ -219,7 +219,7 @@ gocyclo-check:
 	    go get -u github.com/fzipp/gocyclo; \
 		go install $(GOFLAGS) github.com/fzipp/gocyclo; \
 	fi
-	for S in $(GOFILES); do gocyclo -over 33 $$S || exit 1; done;
+	for S in $(GOFILES); do gocyclo -over 47 $$S || exit 1; done;
 
 .PHONY: static-check
 static-check:
diff --git a/pkg/models/list_duplicate.go b/pkg/models/list_duplicate.go
new file mode 100644
index 00000000000..e54cef715fb
--- /dev/null
+++ b/pkg/models/list_duplicate.go
@@ -0,0 +1,299 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-2020 Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package models
+
+import (
+	"code.vikunja.io/api/pkg/files"
+	"code.vikunja.io/api/pkg/utils"
+	"code.vikunja.io/web"
+)
+
+// ListDuplicate holds everything needed to duplicate a list
+type ListDuplicate struct {
+	// The list id of the list to duplicate
+	ListID int64 `json:"-" param:"listid"`
+	// The target namespace ID
+	NamespaceID int64 `json:"namespace_id,omitempty"`
+
+	// The copied list
+	List *List `json:",omitempty"`
+
+	web.Rights   `json:"-"`
+	web.CRUDable `json:"-"`
+}
+
+// CanCreate checks if a user has the right to duplicate a list
+func (ld *ListDuplicate) CanCreate(a web.Auth) (canCreate bool, err error) {
+	// List Exists + user has read access to list
+	ld.List = &List{ID: ld.ListID}
+	canRead, err := ld.List.CanRead(a)
+	if err != nil || !canRead {
+		return canRead, err
+	}
+
+	// Namespace exists + user has write access to is (-> can create new lists)
+	ld.List.NamespaceID = ld.NamespaceID
+	return ld.List.CanCreate(a)
+}
+
+// Create duplicates a list
+// @Summary Duplicate an existing list
+// @Description Copies the list, tasks, files, kanban data, assignees, comments, attachments, lables, relations, backgrounds, user/team rights and link shares from one list to a new namespace. The user needs read access in the list and write access in the namespace of the new list.
+// @tags list
+// @Accept json
+// @Produce json
+// @Security JWTKeyAuth
+// @Param listID path int true "The list ID to duplicate"
+// @Param list body models.ListDuplicate true "The target namespace which should hold the copied list."
+// @Success 200 {object} models.ListDuplicate "The created list."
+// @Failure 400 {object} web.HTTPError "Invalid list duplicate object provided."
+// @Failure 403 {object} web.HTTPError "The user does not have access to the list or namespace"
+// @Failure 500 {object} models.Message "Internal error"
+// @Router /lists/{listID}/duplicate [put]
+func (ld *ListDuplicate) Create(a web.Auth) (err error) {
+
+	ld.List.ID = 0
+	ld.List.Identifier = "" // Reset the identifier to trigger regenerating a new one
+	// Set the owner to the current user
+	ld.List.OwnerID = a.GetID()
+	if err := CreateOrUpdateList(ld.List); err != nil {
+		return err
+	}
+
+	// Duplicate kanban buckets
+	// Old bucket ID as key, new id as value
+	// Used to map the newly created tasks to their new buckets
+	bucketMap := make(map[int64]int64)
+	buckets := []*Bucket{}
+	err = x.Where("list_id = ?", ld.ListID).Find(&buckets)
+	if err != nil {
+		return
+	}
+	for _, b := range buckets {
+		oldID := b.ID
+		b.ID = 0
+		b.ListID = ld.List.ID
+		if err := b.Create(a); err != nil {
+			return err
+		}
+		bucketMap[oldID] = b.ID
+	}
+
+	// Get all tasks + all task details
+	tasks, _, _, err := getTasksForLists([]*List{{ID: ld.ListID}}, &taskOptions{})
+	if err != nil {
+		return err
+	}
+
+	taskMap := make(map[int64]int64)
+	// Create + update all tasks (includes reminders)
+	oldTaskIDs := make([]int64, len(tasks))
+	for _, t := range tasks {
+		oldID := t.ID
+		t.ID = 0
+		t.ListID = ld.List.ID
+		t.BucketID = bucketMap[t.BucketID]
+		t.UID = ""
+		err := createTask(t, a, false)
+		if err != nil {
+			return err
+		}
+		taskMap[oldID] = t.ID
+		oldTaskIDs = append(oldTaskIDs, oldID)
+	}
+
+	// Save all attachments
+	// We also duplicate all underlying files since they could be modified in one list which would result in
+	// file changes in the other list which is not something we want.
+	attachments, err := getTaskAttachmentsByTaskIDs(oldTaskIDs)
+	if err != nil {
+		return err
+	}
+
+	for _, attachment := range attachments {
+		attachment.ID = 0
+		attachment.TaskID = oldTaskIDs[attachment.TaskID]
+		attachment.File = &files.File{ID: attachment.FileID}
+		if err := attachment.File.LoadFileMetaByID(); err != nil {
+			if files.IsErrFileDoesNotExist(err) {
+				continue
+			}
+			return err
+		}
+		if err := attachment.File.LoadFileByID(); err != nil {
+			return err
+		}
+
+		err := attachment.NewAttachment(attachment.File.File, attachment.File.Name, attachment.File.Size, a)
+		if err != nil {
+			return err
+		}
+
+		if attachment.File.File != nil {
+			_ = attachment.File.File.Close()
+		}
+	}
+
+	// Copy label tasks (not the labels)
+	labelTasks := []*LabelTask{}
+	err = x.In("task_id", oldTaskIDs).Find(&labelTasks)
+	if err != nil {
+		return
+	}
+
+	for _, lt := range labelTasks {
+		lt.ID = 0
+		lt.TaskID = taskMap[lt.TaskID]
+		if _, err := x.Insert(lt); err != nil {
+			return err
+		}
+	}
+
+	// Assignees
+	// Only copy those assignees who have access to the task
+	assignees := []*TaskAssginee{}
+	err = x.In("task_id", oldTaskIDs).Find(&assignees)
+	if err != nil {
+		return
+	}
+	for _, a := range assignees {
+		t := &Task{
+			ID:     taskMap[a.TaskID],
+			ListID: ld.List.ID,
+		}
+		if err := t.addNewAssigneeByID(a.UserID, ld.List); err != nil {
+			if IsErrUserDoesNotHaveAccessToList(err) {
+				continue
+			}
+			return err
+		}
+	}
+
+	// Comments
+	comments := []*TaskComment{}
+	err = x.In("task_id", oldTaskIDs).Find(&comments)
+	if err != nil {
+		return
+	}
+	for _, c := range comments {
+		c.ID = 0
+		c.TaskID = taskMap[c.TaskID]
+		if _, err := x.Insert(c); err != nil {
+			return err
+		}
+	}
+
+	// Relations in that list
+	// Low-Effort: Only copy those relations which are between tasks in the same list
+	// because we can do that without a lot of hassle
+	relations := []*TaskRelation{}
+	err = x.In("task_id", oldTaskIDs).Find(&relations)
+	if err != nil {
+		return
+	}
+	for _, r := range relations {
+		otherTaskID, exists := taskMap[r.OtherTaskID]
+		if !exists {
+			continue
+		}
+		r.ID = 0
+		r.OtherTaskID = otherTaskID
+		r.TaskID = taskMap[r.TaskID]
+		if _, err := x.Insert(r); err != nil {
+			return err
+		}
+	}
+
+	// Background files + unsplash info
+	if ld.List.BackgroundFileID != 0 {
+		f := &files.File{ID: ld.List.BackgroundFileID}
+		if err := f.LoadFileMetaByID(); err != nil {
+			return err
+		}
+		if err := f.LoadFileByID(); err != nil {
+			return err
+		}
+		defer f.File.Close()
+
+		file, err := files.Create(f.File, f.Name, f.Size, a)
+		if err != nil {
+			return err
+		}
+
+		// Get unsplash info if applicable
+		up, err := GetUnsplashPhotoByFileID(ld.List.BackgroundFileID)
+		if err != nil && files.IsErrFileIsNotUnsplashFile(err) {
+			return err
+		}
+		if up != nil {
+			up.ID = 0
+			up.FileID = file.ID
+			if err := up.Save(); err != nil {
+				return err
+			}
+		}
+
+		ld.List.BackgroundFileID = file.ID
+		if err := CreateOrUpdateList(ld.List); err != nil {
+			return err
+		}
+	}
+
+	// Rights / Shares
+	// To keep it simple(r) we will only copy rights which are directly used with the list, no namespace changes.
+	users := []*ListUser{}
+	err = x.Where("list_id = ?", ld.ListID).Find(&users)
+	if err != nil {
+		return
+	}
+	for _, u := range users {
+		u.ID = 0
+		u.ListID = ld.List.ID
+		if _, err := x.Insert(u); err != nil {
+			return err
+		}
+	}
+	teams := []*TeamList{}
+	err = x.Where("list_id = ?", ld.ListID).Find(&teams)
+	if err != nil {
+		return
+	}
+	for _, t := range teams {
+		t.ID = 0
+		t.ListID = ld.List.ID
+		if _, err := x.Insert(t); err != nil {
+			return err
+		}
+	}
+
+	// Generate new link shares if any are available
+	linkShares := []*LinkSharing{}
+	err = x.Where("list_id = ?", ld.ListID).Find(&linkShares)
+	if err != nil {
+		return
+	}
+	for _, share := range linkShares {
+		share.ID = 0
+		share.ListID = ld.List.ID
+		share.Hash = utils.MakeRandomString(40)
+		if _, err := x.Insert(share); err != nil {
+			return err
+		}
+	}
+
+	return
+}
diff --git a/pkg/models/list_duplicate_test.go b/pkg/models/list_duplicate_test.go
new file mode 100644
index 00000000000..90176b127c9
--- /dev/null
+++ b/pkg/models/list_duplicate_test.go
@@ -0,0 +1,47 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-2020 Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package models
+
+import (
+	"code.vikunja.io/api/pkg/db"
+	"code.vikunja.io/api/pkg/files"
+	"code.vikunja.io/api/pkg/user"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestListDuplicate(t *testing.T) {
+
+	db.LoadAndAssertFixtures(t)
+	files.InitTestFileFixtures(t)
+
+	u := &user.User{
+		ID: 1,
+	}
+
+	l := &ListDuplicate{
+		ListID:      1,
+		NamespaceID: 1,
+	}
+	can, err := l.CanCreate(u)
+	assert.NoError(t, err)
+	assert.True(t, can)
+	err = l.Create(u)
+	assert.NoError(t, err)
+	// To make this test 100% useful, it would need to assert a lot more stuff, but it is good enough for now.
+	// Also, we're lacking utility functions to do all needed assertions.
+}
diff --git a/pkg/models/list_rights.go b/pkg/models/list_rights.go
index b27f5a8e359..2aab2357f74 100644
--- a/pkg/models/list_rights.go
+++ b/pkg/models/list_rights.go
@@ -98,7 +98,7 @@ func (l *List) CanDelete(a web.Auth) (bool, error) {
 
 // CanCreate checks if the user can create a list
 func (l *List) CanCreate(a web.Auth) (bool, error) {
-	// A user can create a list if he has write access to the namespace
+	// A user can create a list if they have write access to the namespace
 	n := &Namespace{ID: l.NamespaceID}
 	return n.CanWrite(a)
 }
diff --git a/pkg/models/task_attachment.go b/pkg/models/task_attachment.go
index 5b052ebba23..ada1aadf612 100644
--- a/pkg/models/task_attachment.go
+++ b/pkg/models/task_attachment.go
@@ -193,3 +193,45 @@ func (ta *TaskAttachment) Delete() error {
 	}
 	return err
 }
+
+func getTaskAttachmentsByTaskIDs(taskIDs []int64) (attachments []*TaskAttachment, err error) {
+	attachments = []*TaskAttachment{}
+	err = x.
+		In("task_id", taskIDs).
+		Find(&attachments)
+	if err != nil {
+		return
+	}
+
+	fileIDs := []int64{}
+	userIDs := []int64{}
+	for _, a := range attachments {
+		userIDs = append(userIDs, a.CreatedByID)
+		fileIDs = append(fileIDs, a.FileID)
+	}
+
+	// Get all files
+	fs := make(map[int64]*files.File)
+	err = x.In("id", fileIDs).Find(&fs)
+	if err != nil {
+		return
+	}
+
+	users := make(map[int64]*user.User)
+	err = x.In("id", userIDs).Find(&users)
+	if err != nil {
+		return
+	}
+
+	// Obfuscate all user emails
+	for _, u := range users {
+		u.Email = ""
+	}
+
+	for _, a := range attachments {
+		a.CreatedBy = users[a.CreatedByID]
+		a.File = fs[a.FileID]
+	}
+
+	return
+}
diff --git a/pkg/models/tasks.go b/pkg/models/tasks.go
index d63e53a53c4..a3022a52ac9 100644
--- a/pkg/models/tasks.go
+++ b/pkg/models/tasks.go
@@ -18,7 +18,6 @@ package models
 
 import (
 	"code.vikunja.io/api/pkg/config"
-	"code.vikunja.io/api/pkg/files"
 	"code.vikunja.io/api/pkg/metrics"
 	"code.vikunja.io/api/pkg/user"
 	"code.vikunja.io/api/pkg/utils"
@@ -440,26 +439,7 @@ func addMoreInfoToTasks(taskMap map[int64]*Task) (err error) {
 	}
 
 	// Get task attachments
-	attachments := []*TaskAttachment{}
-	err = x.
-		In("task_id", taskIDs).
-		Find(&attachments)
-	if err != nil {
-		return
-	}
-
-	fileIDs := []int64{}
-	for _, a := range attachments {
-		userIDs = append(userIDs, a.CreatedByID)
-		fileIDs = append(fileIDs, a.FileID)
-	}
-
-	// Get all files
-	fs := make(map[int64]*files.File)
-	err = x.In("id", fileIDs).Find(&fs)
-	if err != nil {
-		return
-	}
+	attachments, err := getTaskAttachmentsByTaskIDs(taskIDs)
 
 	// Get all users of a task
 	// aka the ones who created a task
@@ -476,8 +456,6 @@ func addMoreInfoToTasks(taskMap map[int64]*Task) (err error) {
 
 	// Put the users and files in task attachments
 	for _, a := range attachments {
-		a.CreatedBy = users[a.CreatedByID]
-		a.File = fs[a.FileID]
 		taskMap[a.TaskID].Attachments = append(taskMap[a.TaskID].Attachments, a)
 	}
 
@@ -574,6 +552,10 @@ func checkBucketAndTaskBelongToSameList(fullTask *Task, bucketID int64) (err err
 // @Failure 500 {object} models.Message "Internal error"
 // @Router /lists/{id} [put]
 func (t *Task) Create(a web.Auth) (err error) {
+	return createTask(t, a, true)
+}
+
+func createTask(t *Task, a web.Auth, updateAssignees bool) (err error) {
 
 	t.ID = 0
 
@@ -637,8 +619,10 @@ func (t *Task) Create(a web.Auth) (err error) {
 	}
 
 	// Update the assignees
-	if err := t.updateTaskAssignees(t.Assignees); err != nil {
-		return err
+	if updateAssignees {
+		if err := t.updateTaskAssignees(t.Assignees); err != nil {
+			return err
+		}
 	}
 
 	// Update the reminders
diff --git a/pkg/routes/routes.go b/pkg/routes/routes.go
index 57e4abc6326..f5d4205e323 100644
--- a/pkg/routes/routes.go
+++ b/pkg/routes/routes.go
@@ -304,6 +304,13 @@ func registerAPIRoutes(a *echo.Group) {
 	a.POST("/lists/:list/buckets/:bucket", kanbanBucketHandler.UpdateWeb)
 	a.DELETE("/lists/:list/buckets/:bucket", kanbanBucketHandler.DeleteWeb)
 
+	listDuplicateHandler := &handler.WebHandler{
+		EmptyStruct: func() handler.CObject {
+			return &models.ListDuplicate{}
+		},
+	}
+	a.PUT("/lists/:listid/duplicate", listDuplicateHandler.CreateWeb)
+
 	taskHandler := &handler.WebHandler{
 		EmptyStruct: func() handler.CObject {
 			return &models.Task{}