diff --git a/maubot/client.py b/maubot/client.py
index ea7db0d..5b91d8c 100644
--- a/maubot/client.py
+++ b/maubot/client.py
@@ -177,13 +177,13 @@ class Client:
             await self.stop()
 
     async def update_displayname(self, displayname: str) -> None:
-        if not displayname or displayname == self.displayname:
+        if displayname is None or displayname == self.displayname:
             return
         self.db_instance.displayname = displayname
         await self.client.set_displayname(self.displayname)
 
     async def update_avatar_url(self, avatar_url: ContentURI) -> None:
-        if not avatar_url or avatar_url == self.avatar_url:
+        if avatar_url is None or avatar_url == self.avatar_url:
             return
         self.db_instance.avatar_url = avatar_url
         await self.client.set_avatar_url(self.avatar_url)
@@ -198,7 +198,7 @@ class Client:
                                         client_session=self.http_client, log=self.log)
         mxid = await new_client.whoami()
         if mxid != self.id:
-            raise ValueError("MXID mismatch")
+            raise ValueError(f"MXID mismatch: {mxid}")
         new_client.store = self.db_instance
         self.stop_sync()
         self.client = new_client
diff --git a/maubot/management/api/client.py b/maubot/management/api/client.py
index 051f9be..5bee0af 100644
--- a/maubot/management/api/client.py
+++ b/maubot/management/api/client.py
@@ -20,7 +20,7 @@ from http import HTTPStatus
 from aiohttp import web
 
 from mautrix.types import UserID, SyncToken, FilterID
-from mautrix.errors import MatrixRequestError, MatrixInvalidToken
+from mautrix.errors import MatrixRequestError, MatrixConnectionError, MatrixInvalidToken
 from mautrix.client import Client as MatrixClient
 
 from ...db import DBClient
@@ -54,12 +54,14 @@ async def _create_client(user_id: Optional[UserID], data: dict) -> web.Response:
         return resp.bad_client_access_token
     except MatrixRequestError:
         return resp.bad_client_access_details
+    except MatrixConnectionError:
+        return resp.bad_client_connection_details
     if user_id is None:
         existing_client = Client.get(mxid, None)
         if existing_client is not None:
             return resp.user_exists
     elif mxid != user_id:
-        return resp.mxid_mismatch
+        return resp.mxid_mismatch(mxid)
     db_instance = DBClient(id=mxid, homeserver=homeserver, access_token=access_token,
                            enabled=data.get("enabled", True), next_batch=SyncToken(""),
                            filter_id=FilterID(""), sync=data.get("sync", True),
@@ -81,8 +83,8 @@ async def _update_client(client: Client, data: dict) -> web.Response:
         return resp.bad_client_access_token
     except MatrixRequestError:
         return resp.bad_client_access_details
-    except ValueError:
-        return resp.mxid_mismatch
+    except ValueError as e:
+        return resp.mxid_mismatch(str(e)[len("MXID mismatch: "):])
     await client.update_avatar_url(data.get("avatar_url", None))
     await client.update_displayname(data.get("displayname", None))
     await client.update_started(data.get("started", None))
diff --git a/maubot/management/api/responses.py b/maubot/management/api/responses.py
index be9b3b0..5204927 100644
--- a/maubot/management/api/responses.py
+++ b/maubot/management/api/responses.py
@@ -55,9 +55,16 @@ class _Response:
         }, status=HTTPStatus.BAD_REQUEST)
 
     @property
-    def mxid_mismatch(self) -> web.Response:
+    def bad_client_connection_details(self) -> web.Response:
         return web.json_response({
-            "error": "The Matrix user ID of the client and the user ID of the access token don't match",
+            "error": "Could not connect to homeserver",
+            "errcode": "bad_client_connection_details"
+        }, status=HTTPStatus.BAD_REQUEST)
+
+    def mxid_mismatch(self, found: str) -> web.Response:
+        return web.json_response({
+            "error": "The Matrix user ID of the client and the user ID of the access token don't "
+                     f"match. Access token is for user {found}",
             "errcode": "mxid_mismatch",
         }, status=HTTPStatus.BAD_REQUEST)
 
diff --git a/maubot/management/frontend/src/api.js b/maubot/management/frontend/src/api.js
index 8721685..e9fc926 100644
--- a/maubot/management/frontend/src/api.js
+++ b/maubot/management/frontend/src/api.js
@@ -114,9 +114,22 @@ export async function putClient(client) {
     return await resp.json()
 }
 
+export async function deleteClient(id) {
+    const resp = await fetch(`${BASE_PATH}/client/${id}`, {
+        headers: getHeaders(),
+        method: "DELETE",
+    })
+    if (resp.status === 204) {
+        return {
+            "success": true,
+        }
+    }
+    return await resp.json()
+}
+
 export default {
     login, ping,
     getInstances, getInstance,
     getPlugins, getPlugin, uploadPlugin,
-    getClients, getClient, uploadAvatar, putClient,
+    getClients, getClient, uploadAvatar, putClient, deleteClient,
 }
diff --git a/maubot/management/frontend/src/pages/dashboard/Client.js b/maubot/management/frontend/src/pages/dashboard/Client.js
index 2019444..9b7dbd1 100644
--- a/maubot/management/frontend/src/pages/dashboard/Client.js
+++ b/maubot/management/frontend/src/pages/dashboard/Client.js
@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 import React, { Component } from "react"
-import { Link } from "react-router-dom"
+import { Link, withRouter } from "react-router-dom"
 import { ReactComponent as ChevronRight } from "../../res/chevron-right.svg"
 import { ReactComponent as UploadButton } from "../../res/upload.svg"
 import { PrefTable, PrefSwitch, PrefInput } from "../../components/PreferenceTable"
@@ -67,10 +67,24 @@ class Client extends Component {
 
             uploadingAvatar: false,
             saving: false,
+            deleting: false,
             startingOrStopping: false,
+            deleted: false,
+            error: "",
         }
     }
 
+    get clientInState() {
+        const client = Object.assign({}, this.state)
+        delete client.uploadingAvatar
+        delete client.saving
+        delete client.deleting
+        delete client.startingOrStopping
+        delete client.deleted
+        delete client.error
+        return client
+    }
+
     componentWillReceiveProps(nextProps) {
         this.setState(Object.assign(this.initialState, nextProps.client))
     }
@@ -106,12 +120,30 @@ class Client extends Component {
 
     save = async () => {
         this.setState({ saving: true })
-        const resp = await api.putClient(this.state)
+        const resp = await api.putClient(this.clientInState)
         if (resp.id) {
-            resp.saving = false
-            this.setState(resp)
+            this.props.onChange(resp)
+            if (this.isNew) {
+                this.props.history.push(`/client/${resp.id}`)
+            } else {
+                this.setState({ saving: false, error: "" })
+            }
         } else {
-            console.error(resp)
+            this.setState({ saving: false, error: resp.error })
+        }
+    }
+
+    delete = async () => {
+        if (!window.confirm(`Are you sure you want to delete ${this.state.id}?`)) {
+            return
+        }
+        this.setState({ deleting: true })
+        const resp = await api.deleteClient(this.state.id)
+        if (resp.success) {
+            this.props.onDelete()
+            this.props.history.push("/")
+        } else {
+            this.setState({ deleting: false, error: resp.error })
         }
     }
 
@@ -122,42 +154,54 @@ class Client extends Component {
             started: !this.state.started,
         })
         if (resp.id) {
-            resp.startingOrStopping = false
-            this.setState(resp)
+            this.props.onChange(resp)
+            this.setState({ startingOrStopping: false, error: "" })
         } else {
-            console.error(resp)
+            this.setState({ startingOrStopping: false, error: resp.error })
         }
     }
 
+    get loading() {
+        return this.state.saving || this.state.startingOrStopping || this.state.deleting
+    }
+
+    get isNew() {
+        return !Boolean(this.props.client)
+    }
+
     render() {
         return <div className="client">
-            <div className="sidebar">
+            {!this.isNew && <div className="sidebar">
                 <div className={`avatar-container ${this.state.avatar_url ? "" : "no-avatar"}
                         ${this.state.uploadingAvatar ? "uploading" : ""}`}>
                     <img className="avatar" src={getAvatarURL(this.state)} alt="Avatar"/>
                     <UploadButton className="upload"/>
                     <input className="file-selector" type="file" accept="image/png, image/jpeg"
-                           onChange={this.avatarUpload} disabled={this.state.uploadingAvatar}/>
+                           onChange={this.avatarUpload} disabled={this.state.uploadingAvatar}
+                           onDragEnter={evt => evt.target.parentElement.classList.add("drag")}
+                           onDragLeave={evt => evt.target.parentElement.classList.remove("drag")}/>
                     {this.state.uploadingAvatar && <Spinner/>}
                 </div>
-                {this.props.client && (<>
-                    <div className="started-container">
-                        <span className={`started ${this.state.started}`}/>
-                        <span className="text">{this.state.started ? "Started" : "Stopped"}</span>
-                    </div>
-                    <button className="save" onClick={this.startOrStop}
-                            disabled={this.state.saving || this.state.startingOrStopping}>
+                <div className="started-container">
+                    <span className={`started ${this.props.client.started}
+                            ${this.props.client.enabled ? "" : "disabled"}`}/>
+                    <span className="text">
+                        {this.props.client.started ? "Started" :
+                            (this.props.client.enabled ? "Stopped" : "Disabled")}
+                    </span>
+                </div>
+                {(this.props.client.started || this.props.client.enabled) && (
+                    <button className="save" onClick={this.startOrStop} disabled={this.loading}>
                         {this.state.startingOrStopping ? <Spinner/>
-                            : (this.state.started ? "Stop" : "Start")}
+                            : (this.props.client.started ? "Stop" : "Start")}
                     </button>
-                </>)}
-            </div>
+                )}
+            </div>}
             <div className="info-container">
                 <PrefTable>
-                    <PrefInput rowName="User ID" type="text" disabled={!!this.props.client}
-                               name={this.props.client ? "" : "id"}
-                               value={this.state.id} placeholder="@fancybot:example.com"
-                               onChange={this.inputChange}/>
+                    <PrefInput rowName="User ID" type="text" disabled={!this.isNew}
+                               name={!this.isNew ? "" : "id"} value={this.state.id}
+                               placeholder="@fancybot:example.com" onChange={this.inputChange}/>
                     <PrefInput rowName="Display name" type="text" name="displayname"
                                value={this.state.displayname} placeholder="My fancy bot"
                                onChange={this.inputChange}/>
@@ -167,21 +211,33 @@ class Client extends Component {
                     <PrefInput rowName="Access token" type="text" name="access_token"
                                value={this.state.access_token} onChange={this.inputChange}
                                placeholder="MDAxYWxvY2F0aW9uIG1hdHJpeC5sb2NhbAowMDEzaWRlbnRpZmllc"/>
+                    <PrefInput rowName="Avatar URL" type="text" name="avatar_url"
+                               value={this.state.avatar_url} onChange={this.inputChange}
+                               placeholder="mxc://example.com/mbmwyoTvPhEQPiCskcUsppko"/>
                     <PrefSwitch rowName="Sync" active={this.state.sync}
                                 onToggle={sync => this.setState({ sync })}/>
                     <PrefSwitch rowName="Autojoin" active={this.state.autojoin}
                                 onToggle={autojoin => this.setState({ autojoin })}/>
                     <PrefSwitch rowName="Enabled" active={this.state.enabled}
-                                onToggle={enabled => this.setState({ enabled })}/>
+                                onToggle={enabled => this.setState({
+                                    enabled,
+                                    started: enabled && this.state.started,
+                                })}/>
                 </PrefTable>
-
-                <button className="save" onClick={this.save}
-                        disabled={this.state.saving || this.state.startingOrStopping}>
-                    {this.state.saving ? <Spinner/> : "Save"}
-                </button>
+                <div className="buttons">
+                    {!this.isNew && (
+                        <button className="delete" onClick={this.delete} disabled={this.loading}>
+                            {this.state.deleting ? <Spinner/> : "Delete"}
+                        </button>
+                    )}
+                    <button className="save" onClick={this.save} disabled={this.loading}>
+                        {this.state.saving ? <Spinner/> : (this.isNew ? "Create" : "Save")}
+                    </button>
+                </div>
+                <div className="error">{this.state.error}</div>
             </div>
         </div>
     }
 }
 
-export default Client
+export default withRouter(Client)
diff --git a/maubot/management/frontend/src/pages/dashboard/index.js b/maubot/management/frontend/src/pages/dashboard/index.js
index 5d9a38d..2ca434f 100644
--- a/maubot/management/frontend/src/pages/dashboard/index.js
+++ b/maubot/management/frontend/src/pages/dashboard/index.js
@@ -57,6 +57,18 @@ class Dashboard extends Component {
             React.createElement(type, { key: entry.id, [field]: entry }))
     }
 
+    delete(stateField, id) {
+        const data = Object.assign({}, this.state[stateField])
+        delete data[id]
+        this.setState({ [stateField]: data })
+    }
+
+    add(stateField, entry) {
+        const data = Object.assign({}, this.state[stateField])
+        data[entry.id] = entry
+        this.setState({ [stateField]: data })
+    }
+
     renderView(field, type, id) {
         const stateField = field + "s"
         const entry = this.state[stateField][id]
@@ -65,11 +77,8 @@ class Dashboard extends Component {
         }
         return React.createElement(type, {
             [field]: entry,
-            onChange: newEntry => this.setState({
-                [stateField]: Object.assign({}, this.state[stateField], {
-                    [id]: newEntry,
-                }),
-            }),
+            onDelete: () => this.delete(stateField, id),
+            onChange: newEntry => this.add(stateField, newEntry),
         })
     }
 
@@ -111,7 +120,8 @@ class Dashboard extends Component {
                 <Switch>
                     <Route path="/" exact render={() => "Hello, World!"}/>
                     <Route path="/new/instance" render={() => <InstanceView/>}/>
-                    <Route path="/new/client" render={() => <Client/>}/>
+                    <Route path="/new/client" render={() => <Client
+                        onChange={newEntry => this.add("clients", newEntry)}/>}/>
                     <Route path="/new/plugin" render={() => <PluginView/>}/>
                     <Route path="/instance/:id" render={({ match }) =>
                         this.renderView("instance", InstanceView, match.params.id)}/>
diff --git a/maubot/management/frontend/src/style/lib/preferencetable.sass b/maubot/management/frontend/src/style/lib/preferencetable.sass
index 59e6a4a..28ea689 100644
--- a/maubot/management/frontend/src/style/lib/preferencetable.sass
+++ b/maubot/management/frontend/src/style/lib/preferencetable.sass
@@ -48,10 +48,13 @@
 
                 font-size: 1rem
 
-                border-bottom: 1px dotted $primary
+                border-bottom: 1px solid $background
 
-                &:hover:not(:disabled)
-                    border-bottom: 1px solid $primary
+                &:not(:disabled)
+                    border-bottom: 1px dotted $primary
 
-                &:focus:not(:disabled)
-                    border-bottom: 2px solid $primary
+                    &:hover
+                        border-bottom: 1px solid $primary
+
+                    &:focus
+                        border-bottom: 2px solid $primary
diff --git a/maubot/management/frontend/src/style/pages/client.sass b/maubot/management/frontend/src/style/pages/client.sass
index bfb41bc..e0ffb66 100644
--- a/maubot/management/frontend/src/style/pages/client.sass
+++ b/maubot/management/frontend/src/style/pages/client.sass
@@ -21,6 +21,7 @@
     > div.sidebar
         vertical-align: top
         text-align: center
+        width: 8rem
 
         > div
             margin-bottom: 1rem
@@ -68,7 +69,7 @@
                 > input.file-selector
                     cursor: pointer
 
-                &:hover
+                &:hover, &.drag
                     > img.avatar
                         opacity: .25
 
@@ -105,6 +106,10 @@
                     background-color: $error-light
                     box-shadow: 0 0 .75rem .75rem $error-light
 
+                    &.disabled
+                        background-color: $border-color
+                        box-shadow: 0 0 .75rem .75rem $border-color
+
             > span.text
                 display: inline-block
                 margin-left: 1rem
@@ -115,7 +120,19 @@
         margin: 0 1rem
         flex: 1
 
-    button.save
+        > .buttons
+            display: flex
+
+            +button-group
+
+        > .error
+            margin-top: 1rem
+            +notification($error)
+
+            &:empty
+                display: none
+
+    button.save, button.delete
         +button
         +main-color-button
         width: 100%
@@ -126,15 +143,3 @@
             +thick-spinner
             +white-spinner
             width: 2rem
-
-//> .client
-    display: table
-
-    > .field
-        display: table-row
-        width: 100%
-
-        > .name, > .value
-            display: table-cell
-            width: 50%
-            text-align: center