diff --git a/db/migrate/20260420181729_add_closed_at_to_user.rb b/db/migrate/20260420181729_add_closed_at_to_user.rb
new file mode 100644
index 0000000..1487103
--- /dev/null
+++ b/db/migrate/20260420181729_add_closed_at_to_user.rb
@@ -0,0 +1,5 @@
+class AddClosedAtToUser < ActiveRecord::Migration[7.2]
+  def change
+    add_column :users, :closed_at, :datetime
+  end
+end
diff --git a/db/migrate/20260420210736_add_opened_at_to_vote.rb b/db/migrate/20260420210736_add_opened_at_to_vote.rb
new file mode 100644
index 0000000..2629227
--- /dev/null
+++ b/db/migrate/20260420210736_add_opened_at_to_vote.rb
@@ -0,0 +1,5 @@
+class AddOpenedAtToVote < ActiveRecord::Migration[7.2]
+  def change
+    add_column :votes, :opened_at, :datetime
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 5675bc4..c5aee86 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.2].define(version: 2026_03_23_215246) do
+ActiveRecord::Schema[7.2].define(version: 2026_04_20_210736) do
   create_table "candidates", force: :cascade do |t|
     t.integer "vote_id"
     t.string "name"
@@ -46,6 +46,7 @@ ActiveRecord::Schema[7.2].define(version: 2026_03_23_215246) do
     t.datetime "updated_at", null: false
     t.string "reset"
     t.boolean "admin"
+    t.datetime "closed_at"
   end
 
   create_table "votes", force: :cascade do |t|
@@ -57,6 +58,7 @@ ActiveRecord::Schema[7.2].define(version: 2026_03_23_215246) do
     t.datetime "updated_at", null: false
     t.string "state"
     t.integer "reminders"
+    t.datetime "opened_at"
   end
 
   add_foreign_key "ratings", "votes"
diff --git a/vedia.rb b/vedia.rb
index 42ff172..48bc673 100644
--- a/vedia.rb
+++ b/vedia.rb
@@ -120,7 +120,7 @@ end
 
 post '/login' do
   user = User.find_by(email: params[:email].downcase.strip)
-  if user && verify_password(params[:password], user.password)
+  if user && active(user) && verify_password(params[:password], user.password)
     if not user.reset.nil?
       user.reset = nil
       user.save
@@ -154,7 +154,7 @@ post '/reset' do
     erb :reset
   else
     @user = User.find_by(email: params[:email])
-    if @user
+    if @user && active(@user)
       @reset = SecureRandom.uuid
       @user.reset = hash_password(@reset)
       @user.save
@@ -174,7 +174,7 @@ get '/reset/:uuid' do
   User.where.not(reset: nil).each do |user|
     @user = user if verify_password(params[:uuid], user.reset)
   end
-  if @user
+  if @user && active(@user)
     erb :reset_change
   else
     erb :reset_invalid
@@ -186,7 +186,7 @@ post '/reset/:uuid' do
   User.where.not(reset: nil).each do |user|
     @user = user if verify_password(params[:uuid], user.reset)
   end
-  if @user
+  if @user && active(@user)
     @errors = []
     if params[:password].empty?
       @errors << OpenStruct.new(:attribute => :password, :type => :blank)
@@ -223,9 +223,28 @@ get '/users/:id' do
   erb :users_show
 end
 
+get '/users/:id/close' do
+  require_admin_or_self
+  require_active
+  erb :users_close
+end
+
+post '/users/:id/close' do
+  require_admin_or_self
+  require_active
+  @user.closed_at = Time.now.utc
+  @user.save
+  if is_admin
+    redirect "/users/#{@user.id}"
+  else
+    @closed = true
+    session.clear
+    erb :login
+  end
+end
+
 get '/admin' do
   require_admin
-  @users = User.all
   @votes = Vote.all
   erb :admin
 end
@@ -556,7 +575,7 @@ post '/votes/:id/organizers' do
     @errors << OpenStruct.new(:attribute => :email, :type => :invalid)
   else
     user = User.find_by(email: params[:email])
-    if not user
+    if not user or not active(user)
       @errors << OpenStruct.new(:attribute => :email, :type => :unknown)
       @params = params
     elsif @vote.users.exists?(user.id)
@@ -584,7 +603,7 @@ def close_expired_votes
     puts "#{Time.now.utc} Closing vote \"#{vote.title}\" because it expired on #{vote.expire_on}..."
     vote.state = 'closed'
     vote.save
-    all_users_sorted.each do |user|
+    users_for_vote(vote).each do |user|
       puts "#{Time.now.utc} Sending results by email to #{user.email}..."
       mail = Mail.new
       mail.from = settings.admin_email
@@ -602,7 +621,7 @@ def send_reminders
     settings.reminders.slice(vote.reminders..settings.reminders.length-1).each do |reminder|
       minutes_to_expiry = ( vote.expire_on - Time.now.utc ) / 60
       if minutes_to_expiry < reminder[:timeout] / 60
-        all_users_sorted.each do |user|
+        active_users.each do |user|
           if not vote.ratings.collect { |rating| rating.user }.include?(user)
             puts "#{Time.now.utc} Sending reminder #{reminder[:template]} for '#{vote.title}' to #{user.email}..."
             mail = Mail.new
@@ -628,7 +647,13 @@ end
 helpers do
   def current_user
     if session[:user_id]
-      User.find(session[:user_id])
+      user = User.find(session[:user_id])
+      if active(user)
+        return user
+      else
+        session.clear
+        return nil
+      end
     elsif settings.spoof_admin
       session.clear
       session[:timezone] = 'UTC'
@@ -657,6 +682,15 @@ helpers do
     redirect '/' unless is_admin or current_user == @user
   end
 
+  def active(user)
+    user.closed_at.nil?
+  end
+
+  def require_active
+    find_user
+    redirect '/' unless active(@user)
+  end
+
   def find_vote
     @vote = Vote.find_by(secure_id: params[:id])
   end
@@ -669,10 +703,39 @@ helpers do
     @user = User.find(params[:id])
   end
 
-  def all_users_sorted
+  def all_users
     User.all.each.sort_by { |user| user.email }
   end
 
+  def active_users(timestamp = Time.now.utc)
+    users = []
+    User.all.each do |user|
+      if user.created_at < timestamp and ( active(user) or user.closed_at > timestamp )
+        users << user
+      end
+    end
+    users.sort_by { |user| user.email }
+  end
+
+  def users_created_between(min, max)
+    users = []
+    User.all.each do |user|
+      if user.created_at > min and user.created_at < max
+        users << user
+      end
+    end
+    users.sort_by { |user| user.email }
+  end
+
+  def users_for_vote(vote)
+    # Users who were active when the vote was open (or created if not open yet)
+    # Users who were created between the vote was open and the vote was closed (or now if the vote is not closed yet)
+    min = vote.opened_at ? vote.opened_at : vote.created_at
+    max = vote.expire_on ? vote.expire_on : Time.now.utc
+    users = active_users(min) + users_created_between(min, max)
+    users.sort_by { |user| user.email }
+  end
+
   def require_candidate_in_vote
     redirect '/votes/' + @vote.secure_id unless @candidate.vote == @vote
   end
diff --git a/views/admin.erb b/views/admin.erb
index 267cdb2..3b93fc1 100644
--- a/views/admin.erb
+++ b/views/admin.erb
@@ -7,15 +7,17 @@
     <tr>
       <th><%= _("Email") %></th>
       <th><%= _("Created") %></th>
+      <th><%= _("Closed") %></th>
       <th><%= _("Admin") %></th>
       <th><%= _("Votes") %></th>
       <th><%= _("Ratings") %></th>
     </tr>
   </thead>
-  <% @users.sort_by { |user| user.email }.each do |user| %>
+  <% all_users.each do |user| %>
     <tr>
       <td><a href="/users/<%= user.id %>"><%= user.email %></a></td>
       <td><%= format_date(user.created_at) %></td>
+      <td><%= active(user) ? nil : format_date(user.closed_at) %></td>
       <td><%= user.admin %></td>
       <td><%= user.votes.length %></td>
       <td><%= user.ratings.length %></td>
diff --git a/views/login.erb b/views/login.erb
index 1ea317e..e16bb4c 100644
--- a/views/login.erb
+++ b/views/login.erb
@@ -1,5 +1,9 @@
 <h1 class="mb-5"><%= _("Login") %></h1>
 
+<% if @closed %>
+  <p class="alert alert-success mb-4"><%= _("Your account was closed successfully.") %></p>
+<% end %>
+
 <% if @error %>
   <div class="alert alert-warning mb-4">
     <p><%= _("Incorrect email or password.") %></p>
diff --git a/views/users_close.erb b/views/users_close.erb
new file mode 100644
index 0000000..4945b09
--- /dev/null
+++ b/views/users_close.erb
@@ -0,0 +1,11 @@
+<h1 class="mb-5"><%= _("Closing account %{email}") % { email: @user.email } %></h1>
+
+<p><%= _("Do you really want to close the account for %{email}?") % { email: @user.email } %></p>
+
+<p><%= _("Past votes and ratings created by this account will remain available, but the account will no longer be able to log in, create new votes, or participate in open votes.") %></p>
+
+<p><%= _("This action cannot be undone.") %></p>
+
+<form action="/users/<%= @user.id %>/close" method="post" class="mb-5">
+  <button type="submit" class="btn btn-danger"><%= _("Close account") %></button>
+</form>
diff --git a/views/users_show.erb b/views/users_show.erb
index 0101801..61122b5 100644
--- a/views/users_show.erb
+++ b/views/users_show.erb
@@ -4,7 +4,15 @@
 
 <p><%= _("Updated: %{date}") % { date: format_date(@user.updated_at) } %></p>
 
-<p class="mb-5"><%= _("Admin: %{admin}") % { admin: @user.admin ? _("Yes") : _("No") } %></p>
+<p><%= _("Admin: %{admin}") % { admin: @user.admin ? _("Yes") : _("No") } %></p>
+
+<% if @user.closed_at %>
+  <p class="mb-5"><%= _("Closed: %{date}") % { date: format_date(@user.closed_at) } %></p>
+<% else %>
+  <form action="/users/<%= @user.id %>/close" method="get" class="mb-5">
+    <button type="submit" class="btn btn-outline-danger"><%= _("Close account") %></button>
+  </form>
+<% end %>
 
 <h2 class="mb-4"><%= _("Organized votes") %></h2>
 
diff --git a/views/votes_show_closed.erb b/views/votes_show_closed.erb
index b904577..a0f220d 100644
--- a/views/votes_show_closed.erb
+++ b/views/votes_show_closed.erb
@@ -175,7 +175,7 @@
       <% end %>
     </tr>
   </thead>
-  <% all_users_sorted.each do |user| %>
+  <% users_for_vote(@vote).each do |user| %>
   <tr>
     <td><%= user.email %></td>
     <% @vote.candidates.each do |candidate| %>
diff --git a/views/votes_show_open.erb b/views/votes_show_open.erb
index ea19fb5..1eae220 100644
--- a/views/votes_show_open.erb
+++ b/views/votes_show_open.erb
@@ -66,7 +66,7 @@
 <h2 class="mb-4"><%= _("Participants") + " (#{@vote.ratings.collect { |rating| rating.user }.uniq.count})" %></h2>
 
 <ul class="mb-5">
-  <% all_users_sorted.each do |user| %>
+  <% users_for_vote(@vote).each do |user| %>
     <li>
       <% if @vote.ratings.collect { |rating| rating.user }.include?(user) %>
         <span>