diff --git a/app/api/repp/api.rb b/app/api/repp/api.rb
index a726d226c..7858cd625 100644
--- a/app/api/repp/api.rb
+++ b/app/api/repp/api.rb
@@ -4,7 +4,7 @@ module Repp
     prefix :repp
 
     http_basic do |username, password|
-      @current_user ||= APIUser.find_by(username: username, password: password)
+      @current_user ||= ApiUser.find_by(username: username, password: password)
       if @current_user
         true
       else
diff --git a/app/controllers/admin/api_users_controller.rb b/app/controllers/admin/api_users_controller.rb
index e7ac175e8..84344c2e9 100644
--- a/app/controllers/admin/api_users_controller.rb
+++ b/app/controllers/admin/api_users_controller.rb
@@ -1,20 +1,20 @@
 module Admin
-  class APIUsersController < BaseController
+  class ApiUsersController < BaseController
     load_and_authorize_resource
     before_action :set_api_user, only: [:show, :edit, :update, :destroy]
 
     def index
-      @q = APIUser.includes(:registrar).search(params[:q])
+      @q = ApiUser.includes(:registrar).search(params[:q])
       @api_users = @q.result.page(params[:page])
     end
 
     def new
       @registrar = Registrar.find_by(id: params[:registrar_id])
-      @api_user = APIUser.new(registrar: @registrar)
+      @api_user = ApiUser.new(registrar: @registrar)
     end
 
     def create
-      @api_user = APIUser.new(api_user_params)
+      @api_user = ApiUser.new(api_user_params)
 
       if @api_user.save
         flash[:notice] = I18n.t('record_created')
@@ -55,7 +55,7 @@ module Admin
     private
 
     def set_api_user
-      @api_user = APIUser.find(params[:id])
+      @api_user = ApiUser.find(params[:id])
     end
 
     def api_user_params
diff --git a/app/controllers/admin/certificates_controller.rb b/app/controllers/admin/certificates_controller.rb
index f25651c39..a08654db3 100644
--- a/app/controllers/admin/certificates_controller.rb
+++ b/app/controllers/admin/certificates_controller.rb
@@ -7,12 +7,12 @@ module Admin
     end
 
     def new
-      @api_user = APIUser.find(params[:api_user_id])
+      @api_user = ApiUser.find(params[:api_user_id])
       @certificate = Certificate.new(api_user: @api_user)
     end
 
     def create
-      @api_user = APIUser.find(params[:api_user_id])
+      @api_user = ApiUser.find(params[:api_user_id])
 
       crt = certificate_params[:crt].open.read if certificate_params[:crt]
       csr = certificate_params[:csr].open.read if certificate_params[:csr]
@@ -73,7 +73,7 @@ module Admin
     end
 
     def set_api_user
-      @api_user = APIUser.find(params[:api_user_id])
+      @api_user = ApiUser.find(params[:api_user_id])
     end
 
     def certificate_params
diff --git a/app/controllers/api/v1/registrant/auth_controller.rb b/app/controllers/api/v1/registrant/auth_controller.rb
index 0e014da02..7ba0e9199 100644
--- a/app/controllers/api/v1/registrant/auth_controller.rb
+++ b/app/controllers/api/v1/registrant/auth_controller.rb
@@ -1,7 +1,7 @@
 require 'rails5_api_controller_backport'
 require 'auth_token/auth_token_creator'
 
-module API
+module Api
   module V1
     module Registrant
       class AuthController < ActionController::API
diff --git a/app/controllers/api/v1/registrant/base_controller.rb b/app/controllers/api/v1/registrant/base_controller.rb
index 99ff9d90b..510f16745 100644
--- a/app/controllers/api/v1/registrant/base_controller.rb
+++ b/app/controllers/api/v1/registrant/base_controller.rb
@@ -1,7 +1,7 @@
 require 'rails5_api_controller_backport'
 require 'auth_token/auth_token_decryptor'
 
-module API
+module Api
   module V1
     module Registrant
       class BaseController < ActionController::API
diff --git a/app/controllers/api/v1/registrant/domains_controller.rb b/app/controllers/api/v1/registrant/domains_controller.rb
index 308f81709..fdfc6872c 100644
--- a/app/controllers/api/v1/registrant/domains_controller.rb
+++ b/app/controllers/api/v1/registrant/domains_controller.rb
@@ -1,7 +1,7 @@
 require 'rails5_api_controller_backport'
 require 'auth_token/auth_token_decryptor'
 
-module API
+module Api
   module V1
     module Registrant
       class DomainsController < BaseController
diff --git a/app/controllers/epp/sessions_controller.rb b/app/controllers/epp/sessions_controller.rb
index f463f4365..e3e9f3114 100644
--- a/app/controllers/epp/sessions_controller.rb
+++ b/app/controllers/epp/sessions_controller.rb
@@ -7,7 +7,7 @@ class Epp::SessionsController < EppController
 
   def login
     success = true
-    @api_user = APIUser.find_by(login_params)
+    @api_user = ApiUser.find_by(login_params)
 
     webclient_request = ENV['webclient_ips'].split(',').map(&:strip).include?(request.ip)
     if webclient_request && !Rails.env.test? && !Rails.env.development?
diff --git a/app/controllers/registrant/sessions_controller.rb b/app/controllers/registrant/sessions_controller.rb
index cb51a94f5..80a23eb0a 100644
--- a/app/controllers/registrant/sessions_controller.rb
+++ b/app/controllers/registrant/sessions_controller.rb
@@ -95,6 +95,6 @@ class Registrant::SessionsController < Devise::SessionsController
 
   def find_user_by_idc(idc)
     return User.new unless idc
-    APIUser.find_by(identity_code: idc) || User.new
+    ApiUser.find_by(identity_code: idc) || User.new
   end
 end
diff --git a/app/controllers/registrar/current_user_controller.rb b/app/controllers/registrar/current_user_controller.rb
index 3f969ecb2..266e4b915 100644
--- a/app/controllers/registrar/current_user_controller.rb
+++ b/app/controllers/registrar/current_user_controller.rb
@@ -12,7 +12,7 @@ class Registrar
     private
 
     def new_user
-      @new_user ||= APIUser.find(params[:new_user_id])
+      @new_user ||= ApiUser.find(params[:new_user_id])
     end
   end
 end
diff --git a/app/controllers/registrar/sessions_controller.rb b/app/controllers/registrar/sessions_controller.rb
index c369051e6..11841481d 100644
--- a/app/controllers/registrar/sessions_controller.rb
+++ b/app/controllers/registrar/sessions_controller.rb
@@ -26,7 +26,7 @@ class Registrar
         @depp_user.errors.add(:base, :webserver_client_cert_directive_should_be_required)
       end
 
-      @api_user = APIUser.find_by(username: params[:depp_user][:tag], password: params[:depp_user][:password])
+      @api_user = ApiUser.find_by(username: params[:depp_user][:tag], password: params[:depp_user][:password])
 
       unless @api_user
         @depp_user.errors.add(:base, t(:no_such_user))
@@ -53,7 +53,7 @@ class Registrar
     end
 
     def id
-      @user = APIUser.find_by_idc_data_and_allowed(request.env['SSL_CLIENT_S_DN'], request.ip)
+      @user = ApiUser.find_by_idc_data_and_allowed(request.env['SSL_CLIENT_S_DN'], request.ip)
 
       if @user
         sign_in(@user, event: :authentication)
@@ -150,12 +150,12 @@ class Registrar
 
     def find_user_by_idc(idc)
       return User.new unless idc
-      APIUser.find_by(identity_code: idc) || User.new
+      ApiUser.find_by(identity_code: idc) || User.new
     end
 
     def find_user_by_idc_and_allowed(idc)
       return User.new unless idc
-      possible_users = APIUser.where(identity_code: idc) || User.new
+      possible_users = ApiUser.where(identity_code: idc) || User.new
       possible_users.each do |selected_user|
         if selected_user.registrar.white_ips.registrar_area.include_ip?(request.ip)
           return selected_user
diff --git a/app/models/ability.rb b/app/models/ability.rb
index 1bc4ae386..97086110b 100644
--- a/app/models/ability.rb
+++ b/app/models/ability.rb
@@ -10,7 +10,7 @@ class Ability
     case @user.class.to_s
     when 'AdminUser'
       @user.roles&.each { |role| send(role) }
-    when 'APIUser'
+    when 'ApiUser'
       @user.roles&.each { |role| send(role) }
       when 'RegistrantUser'
       static_registrant
@@ -94,7 +94,7 @@ class Ability
     can :manage, ContactVersion
     can :manage, Billing::Price
     can :manage, User
-    can :manage, APIUser
+    can :manage, ApiUser
     can :manage, AdminUser
     can :manage, Certificate
     can :manage, Keyrelay
diff --git a/app/models/api_user.rb b/app/models/api_user.rb
index bee04a954..ce32c4045 100644
--- a/app/models/api_user.rb
+++ b/app/models/api_user.rb
@@ -1,6 +1,6 @@
 require 'open3'
 
-class APIUser < User
+class ApiUser < User
   include EppErrors
 
   def epp_code_map
diff --git a/app/models/concerns/versions.rb b/app/models/concerns/versions.rb
index 50ea935d2..5e2bad90c 100644
--- a/app/models/concerns/versions.rb
+++ b/app/models/concerns/versions.rb
@@ -34,7 +34,7 @@ module Versions
     end
 
     def user_from_id_role_username(str)
-      user = APIUser.find_by(id: $1) if str =~ /^(\d+)-(APIUser:|api-)/
+      user = ApiUser.find_by(id: $1) if str =~ /^(\d+)-(ApiUser:|api-)/
       unless user.present?
         user = AdminUser.find_by(id: $1) if str =~ /^(\d+)-AdminUser:/
         unless user.present?
diff --git a/app/models/epp/domain.rb b/app/models/epp/domain.rb
index 49049665c..749f5310c 100644
--- a/app/models/epp/domain.rb
+++ b/app/models/epp/domain.rb
@@ -490,7 +490,7 @@ class Epp::Domain < Domain
 
   def apply_pending_update!
     preclean_pendings
-    user  = APIUser.find(pending_json['current_user_id'])
+    user  = ApiUser.find(pending_json['current_user_id'])
     frame = Nokogiri::XML(pending_json['frame'])
 
     self.statuses.delete(DomainStatus::PENDING_UPDATE)
diff --git a/app/views/admin/api_users/_form.haml b/app/views/admin/api_users/_form.haml
index 722b98d0d..9a26b9fc8 100644
--- a/app/views/admin/api_users/_form.haml
+++ b/app/views/admin/api_users/_form.haml
@@ -38,7 +38,7 @@
           = f.label :role, nil, class: 'required'
         .col-md-7
           = select_tag 'api_user[roles][]',
-            options_for_select(APIUser::ROLES.map {|x| [x, x] }, @api_user.roles.try(:first)),
+            options_for_select(ApiUser::ROLES.map {|x| [x, x] }, @api_user.roles.try(:first)),
             class: 'form-control selectize'
           .checkbox
             %label{for: 'api_user_active'}
diff --git a/app/views/admin/registrars/_users.html.erb b/app/views/admin/registrars/_users.html.erb
index d85eaaf36..f182e4615 100644
--- a/app/views/admin/registrars/_users.html.erb
+++ b/app/views/admin/registrars/_users.html.erb
@@ -6,8 +6,8 @@
     <table class="table table-hover table-bordered table-condensed">
         <thead>
             <tr>
-                <th class="col-xs-6"><%= APIUser.human_attribute_name :username %></th>
-                <th class="col-xs-6"><%= APIUser.human_attribute_name :active %></th>
+                <th class="col-xs-6"><%= ApiUser.human_attribute_name :username %></th>
+                <th class="col-xs-6"><%= ApiUser.human_attribute_name :active %></th>
             </tr>
         </thead>
 
diff --git a/config/initializers/inflections.rb b/config/initializers/inflections.rb
index b4a84b01d..b4eccb451 100644
--- a/config/initializers/inflections.rb
+++ b/config/initializers/inflections.rb
@@ -12,5 +12,4 @@
 
 ActiveSupport::Inflector.inflections(:en) do |inflect|
   inflect.acronym 'DNS'
-  inflect.acronym 'API'
 end
diff --git a/lib/tasks/import.rake b/lib/tasks/import.rake
index 1d83ec5ef..2fa67a827 100644
--- a/lib/tasks/import.rake
+++ b/lib/tasks/import.rake
@@ -131,7 +131,7 @@ namespace :import do
     ips = []
     temp = []
 
-    existing_ids = APIUser.pluck(:legacy_id)
+    existing_ids = ApiUser.pluck(:legacy_id)
     existing_ips = WhiteIp.pluck(:ipv4)
 
     Legacy::Registrar.all.each do |x|
@@ -143,7 +143,7 @@ namespace :import do
         if y.try(:cert) != 'pki'
 
           if y.try(:cert) == 'idkaart'
-            id_users << APIUser.new({
+            id_users << ApiUser.new({
               username: y.try(:password) ? y.try(:password) : y.try(:password),
               password: ('a'..'z').to_a.shuffle.first(8).join,
               identity_code: y.try(:password) ? y.try(:password) : y.try(:password),
@@ -152,7 +152,7 @@ namespace :import do
               legacy_id: y.try(:id)
               })
           else
-            temp << APIUser.new({
+            temp << ApiUser.new({
               username: x.handle.try(:strip),
               password: y.try(:password) ? y.try(:password) : ('a'..'z').to_a.shuffle.first(8).join,
               registrar_id: Registrar.find_by(legacy_id: x.try(:id)).try(:id),
@@ -181,8 +181,8 @@ namespace :import do
       end
     end
 
-    APIUser.import id_users, validate: false
-    APIUser.import users, validate: false
+    ApiUser.import id_users, validate: false
+    ApiUser.import users, validate: false
 
     if ips
       WhiteIp.import ips, validate: false
diff --git a/spec/factories/api_user.rb b/spec/factories/api_user.rb
index 31355f141..a3f9623b6 100644
--- a/spec/factories/api_user.rb
+++ b/spec/factories/api_user.rb
@@ -1,7 +1,7 @@
 FactoryBot.define do
   factory :api_user do
     sequence(:username) { |n| "test#{n}" }
-    password 'a' * APIUser.min_password_length
+    password 'a' * ApiUser.min_password_length
     roles ['super']
     registrar
 
diff --git a/spec/models/api_user_spec.rb b/spec/models/api_user_spec.rb
index b710a05c9..89feeac6d 100644
--- a/spec/models/api_user_spec.rb
+++ b/spec/models/api_user_spec.rb
@@ -1,16 +1,16 @@
 require 'rails_helper'
 
-RSpec.describe APIUser do
+RSpec.describe ApiUser do
   context 'with invalid attribute' do
     before do
-      @api_user = APIUser.new
+      @api_user = ApiUser.new
     end
 
     it 'should not be valid' do
       @api_user.valid?
       @api_user.errors.full_messages.should match_array([
         "Password Password is missing",
-        "Password is too short (minimum is #{APIUser.min_password_length} characters)",
+        "Password is too short (minimum is #{ApiUser.min_password_length} characters)",
         "Registrar Registrar is missing",
         "Username Username is missing",
         "Roles is missing"
diff --git a/spec/models/domain_spec.rb b/spec/models/domain_spec.rb
index 007b1e3de..6b282d651 100644
--- a/spec/models/domain_spec.rb
+++ b/spec/models/domain_spec.rb
@@ -316,10 +316,10 @@ RSpec.describe Domain do
           @api_user = create(:api_user)
           @user.id.should == 1
           @api_user.id.should == 2
-          ::PaperTrail.whodunnit = '2-APIUser: testuser'
+          ::PaperTrail.whodunnit = '2-ApiUser: testuser'
 
           @domain = create(:domain)
-          @domain.creator_str.should == '2-APIUser: testuser'
+          @domain.creator_str.should == '2-ApiUser: testuser'
 
           @domain.creator.should == @api_user
           @domain.creator.should_not == @user
diff --git a/spec/presenters/user_presenter_spec.rb b/spec/presenters/user_presenter_spec.rb
index c0cff114b..ba9e1673f 100644
--- a/spec/presenters/user_presenter_spec.rb
+++ b/spec/presenters/user_presenter_spec.rb
@@ -4,7 +4,7 @@ RSpec.describe UserPresenter do
   let(:presenter) { described_class.new(user: user, view: view) }
 
   describe '#login_with_role' do
-    let(:user) { instance_double(APIUser,
+    let(:user) { instance_double(ApiUser,
                                  login: 'login',
                                  roles: %w[role],
                                  registrar_name: 'registrar') }
diff --git a/test/fixtures/users.yml b/test/fixtures/users.yml
index 9d3001959..5fd2dc925 100644
--- a/test/fixtures/users.yml
+++ b/test/fixtures/users.yml
@@ -1,7 +1,7 @@
 api_bestnames:
   username: test_bestnames
   password: testtest
-  type: APIUser
+  type: ApiUser
   registrar: bestnames
   active: true
   roles:
@@ -10,7 +10,7 @@ api_bestnames:
 api_goodnames:
   username: test_goodnames
   password: testtest
-  type: APIUser
+  type: ApiUser
   registrar: goodnames
   active: true
   roles:
diff --git a/test/system/api/registrant/registrant_api_authentication_test.rb b/test/system/api/registrant/registrant_api_authentication_test.rb
index 9ed518caa..94693ddd5 100644
--- a/test/system/api/registrant/registrant_api_authentication_test.rb
+++ b/test/system/api/registrant/registrant_api_authentication_test.rb
@@ -1,6 +1,6 @@
 require 'test_helper'
 
-class RegistrantAPIAuthenticationTest < ApplicationSystemTestCase
+class RegistrantApiAuthenticationTest < ApplicationSystemTestCase
   def setup
     super
 
diff --git a/test/system/api/registrant/registrant_api_domains_test.rb b/test/system/api/registrant/registrant_api_domains_test.rb
index ab08b4ba2..da5813518 100644
--- a/test/system/api/registrant/registrant_api_domains_test.rb
+++ b/test/system/api/registrant/registrant_api_domains_test.rb
@@ -1,7 +1,7 @@
 require 'test_helper'
 require 'auth_token/auth_token_creator'
 
-class RegistrantAPIDomainsTest < ApplicationSystemTestCase
+class RegistrantApiDomainsTest < ApplicationSystemTestCase
   def setup
     super