diff --git a/src/main/res/values/strings.xml b/src/main/res/values/strings.xml
index 2ade6d2bfc38a05ce1a4c005c717f2f03deca25a..f401c0f4565d8f0bd9c650e6b4a9a069275650d9 100644
--- a/src/main/res/values/strings.xml
+++ b/src/main/res/values/strings.xml
@@ -761,8 +761,13 @@
     <string name="search_countries">Search countries</string>
     <string name="verify_x">Verify %s</string>
     <string name="we_have_sent_you_an_sms"><![CDATA[We have sent you an SMS to <b>%s</b>.]]></string>
-    <string name="please_enter_pin">Please enter the 6 digit pin below.</string>
+    <string name="please_enter_pin_below">Please enter the 6 digit pin below.</string>
     <string name="resend_sms">Resend SMS</string>
     <string name="back">back</string>
     <string name="possible_pin">Automatically pasted possible pin from clipboard.</string>
+    <string name="please_enter_pin">Please enter your 6 digit pin.</string>
+    <string name="abort_registration_procedure">Are you sure you want to abort the registration procedure?</string>
+    <string name="yes">Yes</string>
+    <string name="no">No</string>
+    <string name="verifying">Verifying…</string>
 </resources>
diff --git a/src/main/res/values/styles.xml b/src/main/res/values/styles.xml
index e0765c0c243f47e24a154bfcf47e45234548ece1..57c55b5726d16599fa97b44d131b467cdc1782a2 100644
--- a/src/main/res/values/styles.xml
+++ b/src/main/res/values/styles.xml
@@ -63,6 +63,10 @@
         <item name="android:textSize">?TextSizeBody2</item>
     </style>
 
+    <style name="Widget.Conversations.Button.Borderless.Primary" parent="Widget.Conversations.Button.Borderless">
+        <item name="android:textColor">?colorAccent</item>
+    </style>
+
 
     <style name="TextAppearance.Conversations.Design.Hint" parent="TextAppearance.Design.Hint">
         <item name="android:textSize">?TextSizeCaption</item>
diff --git a/src/quick/java/eu/siacs/conversations/services/QuickConversationsService.java b/src/quick/java/eu/siacs/conversations/services/QuickConversationsService.java
index 01d7cd66158befae0aa226dcbcb44c9fff144c4c..7b73df8d9727f1c67a8ecb088c866922ae98a6f5 100644
--- a/src/quick/java/eu/siacs/conversations/services/QuickConversationsService.java
+++ b/src/quick/java/eu/siacs/conversations/services/QuickConversationsService.java
@@ -7,6 +7,7 @@ import java.security.SecureRandom;
 import java.util.Collections;
 import java.util.Set;
 import java.util.WeakHashMap;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 import eu.siacs.conversations.Config;
 import eu.siacs.conversations.entities.Account;
@@ -20,7 +21,9 @@ public class QuickConversationsService {
     private final XmppConnectionService service;
 
     private final Set<OnVerificationRequested> mOnVerificationRequested = Collections.newSetFromMap(new WeakHashMap<>());
-    private final Set<OnVerified> mOnVerified = Collections.newSetFromMap(new WeakHashMap<>());
+    private final Set<OnVerification> mOnVerification = Collections.newSetFromMap(new WeakHashMap<>());
+
+    private final AtomicBoolean mVerificationInProgress = new AtomicBoolean(false);
 
     QuickConversationsService(XmppConnectionService xmppConnectionService) {
         this.service = xmppConnectionService;
@@ -38,6 +41,18 @@ public class QuickConversationsService {
         }
     }
 
+    public void addOnVerificationListener(OnVerification onVerification) {
+        synchronized (mOnVerification) {
+            mOnVerification.add(onVerification);
+        }
+    }
+
+    public void removeOnVerificationListener(OnVerification onVerification) {
+        synchronized (mOnVerification) {
+            mOnVerification.remove(onVerification);
+        }
+    }
+
     public void requestVerification(Phonenumber.PhoneNumber phoneNumber) {
         String local = PhoneNumberUtilWrapper.normalize(service, phoneNumber);
         Log.d(Config.LOGTAG,"requesting verification for "+PhoneNumberUtilWrapper.normalize(service,phoneNumber));
@@ -52,12 +67,35 @@ public class QuickConversationsService {
         }
     }
 
+    public void verify(Account account, String pin) {
+        if (mVerificationInProgress.compareAndSet(false, true)) {
+            new Thread(() -> {
+                try {
+                    Thread.sleep(5000);
+                    synchronized (mOnVerification) {
+                        for (OnVerification onVerification : mOnVerification) {
+                            onVerification.onVerificationFailed();
+                        }
+                    }
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                } finally {
+                    mVerificationInProgress.set(false);
+                }
+            }).start();
+        }
+    }
+
+    public boolean isVerifying() {
+        return mVerificationInProgress.get();
+    }
+
     public interface OnVerificationRequested {
         void onVerificationRequestFailed(int code);
         void onVerificationRequested();
     }
 
-    public interface OnVerified {
+    public interface OnVerification {
         void onVerificationFailed();
         void onVerificationSucceeded();
     }
diff --git a/src/quick/java/eu/siacs/conversations/ui/VerifyActivity.java b/src/quick/java/eu/siacs/conversations/ui/VerifyActivity.java
index f798d782da3fda5c69c9ee757c0c6d6140f11bc0..f1425e2722f3a0bb204b618b8246095ac642d7b9 100644
--- a/src/quick/java/eu/siacs/conversations/ui/VerifyActivity.java
+++ b/src/quick/java/eu/siacs/conversations/ui/VerifyActivity.java
@@ -1,5 +1,6 @@
 package eu.siacs.conversations.ui;
 
+import android.app.AlertDialog;
 import android.content.ClipData;
 import android.content.ClipDescription;
 import android.content.ClipboardManager;
@@ -12,30 +13,31 @@ import android.support.v7.widget.Toolbar;
 import android.text.Html;
 import android.view.View;
 
-import java.util.ArrayList;
-
 import eu.siacs.conversations.R;
 import eu.siacs.conversations.databinding.ActivityVerifyBinding;
 import eu.siacs.conversations.entities.Account;
+import eu.siacs.conversations.services.QuickConversationsService;
 import eu.siacs.conversations.ui.util.PinEntryWrapper;
 import eu.siacs.conversations.utils.AccountUtils;
 import eu.siacs.conversations.utils.PhoneNumberUtilWrapper;
 
 import static android.content.ClipDescription.MIMETYPE_TEXT_PLAIN;
 
-public class VerifyActivity extends XmppActivity implements ClipboardManager.OnPrimaryClipChangedListener {
+public class VerifyActivity extends XmppActivity implements ClipboardManager.OnPrimaryClipChangedListener, QuickConversationsService.OnVerification {
 
     private ActivityVerifyBinding binding;
     private Account account;
     private PinEntryWrapper pinEntryWrapper;
     private ClipboardManager clipboardManager;
     private String pasted = null;
+    private boolean verifying = false;
 
 
     @Override
     protected void onCreate(final Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         String pin = savedInstanceState != null ? savedInstanceState.getString("pin") : null;
+        boolean verifying = savedInstanceState != null && savedInstanceState.getBoolean("verifying");
         this.pasted = savedInstanceState != null ? savedInstanceState.getString("pasted") : null;
         this.binding = DataBindingUtil.setContentView(this, R.layout.activity_verify);
         setSupportActionBar((Toolbar) this.binding.toolbar);
@@ -44,18 +46,59 @@ public class VerifyActivity extends XmppActivity implements ClipboardManager.OnP
             this.pinEntryWrapper.setPin(pin);
         }
         binding.back.setOnClickListener(this::onBackButton);
+        binding.next.setOnClickListener(this::onNextButton);
         clipboardManager = (ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
+        setVerifyingState(verifying);
     }
 
     private void onBackButton(View view) {
+        if (this.verifying) {
+            setVerifyingState(false);
+            return;
+        }
+        final Intent intent = new Intent(this, EnterPhoneNumberActivity.class);
         if (this.account != null) {
-            xmppConnectionService.deleteAccount(account);
-            Intent intent = new Intent(this, EnterPhoneNumberActivity.class);
+            AlertDialog.Builder builder = new AlertDialog.Builder(this);
+            builder.setMessage(R.string.abort_registration_procedure);
+            builder.setPositiveButton(R.string.yes, (dialog, which) -> {
+                xmppConnectionService.deleteAccount(account);
+                startActivity(intent);
+                finish();
+            });
+            builder.setNegativeButton(R.string.no, null);
+            builder.create().show();
+        } else {
             startActivity(intent);
             finish();
         }
     }
 
+    private void onNextButton(View view) {
+        final String pin = pinEntryWrapper.getPin();
+        if (PinEntryWrapper.isValidPin(pin)) {
+            if (account != null && xmppConnectionService != null) {
+                setVerifyingState(true);
+                xmppConnectionService.getQuickConversationsService().verify(account, pin);
+            }
+        } else {
+            AlertDialog.Builder builder = new AlertDialog.Builder(this);
+            builder.setMessage(R.string.please_enter_pin);
+            builder.setPositiveButton(R.string.ok, null);
+            builder.create().show();
+        }
+    }
+
+    private void setVerifyingState(boolean verifying) {
+        this.verifying = verifying;
+        this.binding.back.setText(verifying ? R.string.cancel : R.string.back);
+        this.binding.next.setEnabled(!verifying);
+        this.binding.next.setText(verifying ? R.string.verifying : R.string.next);
+        this.binding.resendSms.setVisibility(verifying ? View.GONE : View.VISIBLE);
+        pinEntryWrapper.setEnabled(!verifying);
+        this.binding.progressBar.setVisibility(verifying ? View.VISIBLE : View.GONE);
+        this.binding.progressBar.setIndeterminate(verifying);
+    }
+
     @Override
     protected void refreshUiReal() {
 
@@ -63,16 +106,19 @@ public class VerifyActivity extends XmppActivity implements ClipboardManager.OnP
 
     @Override
     void onBackendConnected() {
+        xmppConnectionService.getQuickConversationsService().addOnVerificationListener(this);
         this.account = AccountUtils.getFirst(xmppConnectionService);
         if (this.account == null) {
             return;
         }
         this.binding.weHaveSent.setText(Html.fromHtml(getString(R.string.we_have_sent_you_an_sms, PhoneNumberUtilWrapper.prettyPhoneNumber(this, this.account.getJid()))));
+        setVerifyingState(xmppConnectionService.getQuickConversationsService().isVerifying());
     }
 
     @Override
     public void onSaveInstanceState(Bundle savedInstanceState) {
         savedInstanceState.putString("pin", this.pinEntryWrapper.getPin());
+        savedInstanceState.putBoolean("verifying", this.verifying);
         if (this.pasted != null) {
             savedInstanceState.putString("pasted", this.pasted);
         }
@@ -89,6 +135,9 @@ public class VerifyActivity extends XmppActivity implements ClipboardManager.OnP
     public void onStop() {
         super.onStop();
         clipboardManager.removePrimaryClipChangedListener(this);
+        if (xmppConnectionService != null) {
+            xmppConnectionService.getQuickConversationsService().removeOnVerificationListener(this);
+        }
     }
 
     @Override
@@ -105,7 +154,7 @@ public class VerifyActivity extends XmppActivity implements ClipboardManager.OnP
             final ClipData primaryClip = clipboardManager.getPrimaryClip();
             if (primaryClip != null && primaryClip.getItemCount() > 0) {
                 final CharSequence clip = primaryClip.getItemAt(0).getText();
-                if (PinEntryWrapper.isPin(clip) && !clip.toString().equals(this.pasted)) {
+                if (PinEntryWrapper.isValidPin(clip) && !clip.toString().equals(this.pasted)) {
                     this.pasted = clip.toString();
                     pinEntryWrapper.setPin(clip.toString());
                     final Snackbar snackbar = Snackbar.make(binding.coordinator, R.string.possible_pin, Snackbar.LENGTH_LONG);
@@ -123,4 +172,16 @@ public class VerifyActivity extends XmppActivity implements ClipboardManager.OnP
             pastePinFromClipboard();
         }
     }
+
+    @Override
+    public void onVerificationFailed() {
+        runOnUiThread(() -> {
+            setVerifyingState(false);
+        });
+    }
+
+    @Override
+    public void onVerificationSucceeded() {
+
+    }
 }
diff --git a/src/quick/java/eu/siacs/conversations/ui/util/PinEntryWrapper.java b/src/quick/java/eu/siacs/conversations/ui/util/PinEntryWrapper.java
index 12d6e88ea34b93ba23de084572e77879ba70b444..17da72798f11cea29f1eb596a98ea63a4239107c 100644
--- a/src/quick/java/eu/siacs/conversations/ui/util/PinEntryWrapper.java
+++ b/src/quick/java/eu/siacs/conversations/ui/util/PinEntryWrapper.java
@@ -64,7 +64,8 @@ public class PinEntryWrapper {
         }
         if (v instanceof EditText) {
             final EditText editText = (EditText) v;
-            if (keyCode == KeyEvent.KEYCODE_DEL && editText.getText().length() == 0) {
+            final boolean cursorAtZero = editText.getSelectionEnd() == 0 && editText.getSelectionStart() == 0;
+            if (keyCode == KeyEvent.KEYCODE_DEL && (cursorAtZero || editText.getText().length() == 0)) {
                 final int current = digits.indexOf(editText);
                 for (int i = current - 1; i >= 0; --i) {
                     if (digits.get(i).getText().length() > 0) {
@@ -100,7 +101,7 @@ public class PinEntryWrapper {
 
     public String getPin() {
         char[] chars = new char[digits.size()];
-        for(int i = 0; i < chars.length; ++i) {
+        for (int i = 0; i < chars.length; ++i) {
             final String input = digits.get(i).getText().toString();
             chars[i] = input.length() != 1 ? ' ' : input.charAt(0);
         }
@@ -109,7 +110,7 @@ public class PinEntryWrapper {
 
     public void setPin(String pin) {
         char[] chars = pin.toCharArray();
-        for(int i = 0; i < digits.size(); ++i) {
+        for (int i = 0; i < digits.size(); ++i) {
             if (i < chars.length) {
                 final Editable editable = digits.get(i).getText();
                 editable.clear();
@@ -118,8 +119,17 @@ public class PinEntryWrapper {
         }
     }
 
-    public boolean isEmpty() {
+    public void setEnabled(boolean enabled) {
         for(EditText digit : digits) {
+            digit.setEnabled(enabled);
+            digit.setCursorVisible(enabled);
+            digit.setFocusable(enabled);
+            digit.setFocusableInTouchMode(enabled);
+        }
+    }
+
+    public boolean isEmpty() {
+        for (EditText digit : digits) {
             if (digit.getText().length() > 0) {
                 return false;
             }
@@ -127,12 +137,12 @@ public class PinEntryWrapper {
         return true;
     }
 
-    public static boolean isPin(CharSequence pin) {
+    public static boolean isValidPin(CharSequence pin) {
         return pin != null && PIN_STRING_PATTERN.matcher(pin).matches();
     }
 
     public void clear() {
-        for(int i = digits.size() - 1; i >= 0; --i) {
+        for (int i = digits.size() - 1; i >= 0; --i) {
             digits.get(i).getText().clear();
         }
     }
diff --git a/src/quick/res/layout/activity_verify.xml b/src/quick/res/layout/activity_verify.xml
index 4fd66f4f29a3375e617dd3a39b5fb78b2a57ff9b..4d44883a0c3ae2664753d065a78c8e2021d60b6c 100644
--- a/src/quick/res/layout/activity_verify.xml
+++ b/src/quick/res/layout/activity_verify.xml
@@ -45,7 +45,7 @@
                         <TextView
                             android:layout_width="wrap_content"
                             android:layout_height="wrap_content"
-                            android:text="@string/please_enter_pin"
+                            android:text="@string/please_enter_pin_below"
                             android:textAppearance="@style/TextAppearance.Conversations.Body1" />
                     </LinearLayout>
 
@@ -150,13 +150,12 @@
 
                     <Button
                         android:id="@+id/next"
-                        style="@style/Widget.Conversations.Button.Borderless"
+                        style="@style/Widget.Conversations.Button.Borderless.Primary"
                         android:layout_width="wrap_content"
                         android:layout_height="wrap_content"
                         android:layout_alignParentEnd="true"
                         android:layout_alignParentBottom="true"
-                        android:text="@string/next"
-                        android:textColor="?colorAccent" />
+                        android:text="@string/next"/>
 
                     <Button
                         android:id="@+id/back"
@@ -177,6 +176,14 @@
                         android:layout_centerHorizontal="true"
                         android:text="@string/resend_sms"
                         android:textColor="?android:textColorSecondary" />
+
+                    <ProgressBar
+                        android:id="@+id/progressBar"
+                        style="?android:attr/progressBarStyle"
+                        android:layout_width="wrap_content"
+                        android:layout_height="wrap_content"
+                        android:layout_centerHorizontal="true"
+                        android:layout_below="@+id/pin_box" />
                 </RelativeLayout>
             </ScrollView>
         </android.support.design.widget.CoordinatorLayout>