diff --git a/backend/src/auth/INALIENABLE_RIGHTS.ts b/backend/src/auth/INALIENABLE_RIGHTS.ts
index adca3640f..25a4fa76d 100644
--- a/backend/src/auth/INALIENABLE_RIGHTS.ts
+++ b/backend/src/auth/INALIENABLE_RIGHTS.ts
@@ -8,4 +8,5 @@ export const INALIENABLE_RIGHTS = [
   RIGHTS.SET_PASSWORD,
   RIGHTS.QUERY_TRANSACTION_LINK,
   RIGHTS.QUERY_OPT_IN,
+  RIGHTS.CHECK_USERNAME,
 ]
diff --git a/backend/src/auth/RIGHTS.ts b/backend/src/auth/RIGHTS.ts
index df4eed8a1..b3627ff7a 100644
--- a/backend/src/auth/RIGHTS.ts
+++ b/backend/src/auth/RIGHTS.ts
@@ -34,6 +34,7 @@ export enum RIGHTS {
   LIST_ALL_CONTRIBUTION_MESSAGES = 'LIST_ALL_CONTRIBUTION_MESSAGES',
   OPEN_CREATIONS = 'OPEN_CREATIONS',
   USER = 'USER',
+  CHECK_USERNAME = 'CHECK_USERNAME',
   // Admin
   SEARCH_USERS = 'SEARCH_USERS',
   SET_USER_ROLE = 'SET_USER_ROLE',
diff --git a/backend/src/graphql/resolver/UserResolver.test.ts b/backend/src/graphql/resolver/UserResolver.test.ts
index 7d71d74b1..f46d0a9bc 100644
--- a/backend/src/graphql/resolver/UserResolver.test.ts
+++ b/backend/src/graphql/resolver/UserResolver.test.ts
@@ -53,6 +53,7 @@ import {
   searchAdminUsers,
   searchUsers,
   user as userQuery,
+  checkUsername,
 } from '@/seeds/graphql/queries'
 import { bibiBloxberg } from '@/seeds/users/bibi-bloxberg'
 import { bobBaumeister } from '@/seeds/users/bob-baumeister'
@@ -2442,6 +2443,34 @@ describe('UserResolver', () => {
       })
     })
   })
+
+  describe('check username', () => {
+    describe('reserved alias', () => {
+      it('returns false', async () => {
+        await expect(
+          query({ query: checkUsername, variables: { username: 'root' } }),
+        ).resolves.toMatchObject({
+          data: {
+            checkUsername: false,
+          },
+          errors: undefined,
+        })
+      })
+    })
+
+    describe('valid alias', () => {
+      it('returns true', async () => {
+        await expect(
+          query({ query: checkUsername, variables: { username: 'valid' } }),
+        ).resolves.toMatchObject({
+          data: {
+            checkUsername: true,
+          },
+          errors: undefined,
+        })
+      })
+    })
+  })
 })
 
 describe('printTimeDuration', () => {
diff --git a/backend/src/graphql/resolver/UserResolver.ts b/backend/src/graphql/resolver/UserResolver.ts
index 0afbfcc5a..a19d9e7d7 100644
--- a/backend/src/graphql/resolver/UserResolver.ts
+++ b/backend/src/graphql/resolver/UserResolver.ts
@@ -498,6 +498,17 @@ export class UserResolver {
     return true
   }
 
+  @Authorized([RIGHTS.CHECK_USERNAME])
+  @Query(() => Boolean)
+  async checkUsername(@Arg('username') username: string): Promise<boolean> {
+    try {
+      await validateAlias(username)
+      return true
+    } catch {
+      return false
+    }
+  }
+
   @Authorized([RIGHTS.UPDATE_USER_INFOS])
   @Mutation(() => Boolean)
   async updateUserInfos(
diff --git a/backend/src/seeds/graphql/queries.ts b/backend/src/seeds/graphql/queries.ts
index bc8fa95e8..ce7efbfc3 100644
--- a/backend/src/seeds/graphql/queries.ts
+++ b/backend/src/seeds/graphql/queries.ts
@@ -22,6 +22,12 @@ export const queryOptIn = gql`
   }
 `
 
+export const checkUsername = gql`
+  query ($username: String!) {
+    checkUsername(username: $username)
+  }
+`
+
 export const transactionsQuery = gql`
   query ($currentPage: Int = 1, $pageSize: Int = 25, $order: Order = DESC) {
     transactionList(currentPage: $currentPage, pageSize: $pageSize, order: $order) {
diff --git a/frontend/src/components/Inputs/InputPasswordConfirmation.vue b/frontend/src/components/Inputs/InputPasswordConfirmation.vue
index 56d58d9ad..900cc0a0a 100644
--- a/frontend/src/components/Inputs/InputPasswordConfirmation.vue
+++ b/frontend/src/components/Inputs/InputPasswordConfirmation.vue
@@ -8,7 +8,7 @@
             containsLowercaseCharacter: true,
             containsUppercaseCharacter: true,
             containsNumericCharacter: true,
-            atLeastEightCharactera: true,
+            atLeastEightCharacters: true,
             atLeastOneSpecialCharater: true,
             noWhitespaceCharacters: true,
           }"
diff --git a/frontend/src/components/Inputs/InputUsername.vue b/frontend/src/components/Inputs/InputUsername.vue
new file mode 100644
index 000000000..e2048a781
--- /dev/null
+++ b/frontend/src/components/Inputs/InputUsername.vue
@@ -0,0 +1,71 @@
+<template>
+  <validation-provider
+    tag="div"
+    :rules="rules"
+    :name="name"
+    :bails="!showAllErrors"
+    :immediate="immediate"
+    vid="username"
+    v-slot="{ errors, valid, validated, ariaInput, ariaMsg }"
+  >
+    <b-form-group :label-for="labelFor">
+      <b-form-input
+        v-model="currentValue"
+        v-bind="ariaInput"
+        :id="labelFor"
+        :name="name"
+        :placeholder="placeholder"
+        type="text"
+        :state="validated ? valid : false"
+        autocomplete="off"
+      ></b-form-input>
+      <b-form-invalid-feedback v-bind="ariaMsg">
+        <div v-if="showAllErrors">
+          <span v-for="error in errors" :key="error">
+            {{ error }}
+            <br />
+          </span>
+        </div>
+        <div v-else>
+          {{ errors[0] }}
+        </div>
+      </b-form-invalid-feedback>
+    </b-form-group>
+  </validation-provider>
+</template>
+<script>
+export default {
+  name: 'InputUsername',
+  props: {
+    rules: {
+      default: () => {
+        return {
+          required: true,
+        }
+      },
+    },
+    name: { type: String, default: 'username' },
+    label: { type: String, default: 'Username' },
+    placeholder: { type: String, default: 'Username' },
+    value: { required: true, type: String },
+    showAllErrors: { type: Boolean, default: false },
+    immediate: { type: Boolean, default: false },
+    unique: { type: Boolean, required: true },
+  },
+  data() {
+    return {
+      currentValue: this.value,
+    }
+  },
+  computed: {
+    labelFor() {
+      return this.name + '-input-field'
+    },
+  },
+  watch: {
+    currentValue() {
+      this.$emit('input', this.currentValue)
+    },
+  },
+}
+</script>
diff --git a/frontend/src/components/UserSettings/UserName.spec.js b/frontend/src/components/UserSettings/UserName.spec.js
new file mode 100644
index 000000000..012ba367a
--- /dev/null
+++ b/frontend/src/components/UserSettings/UserName.spec.js
@@ -0,0 +1,157 @@
+import { mount } from '@vue/test-utils'
+import UserName from './UserName'
+import flushPromises from 'flush-promises'
+
+import { toastErrorSpy, toastSuccessSpy } from '@test/testSetup'
+
+const localVue = global.localVue
+
+const mockAPIcall = jest.fn()
+
+const storeCommitMock = jest.fn()
+
+describe('UserName Form', () => {
+  let wrapper
+
+  const mocks = {
+    $t: jest.fn((t) => t),
+    $store: {
+      state: {
+        username: 'peter',
+      },
+      commit: storeCommitMock,
+    },
+    $apollo: {
+      mutate: mockAPIcall,
+    },
+  }
+
+  const Wrapper = () => {
+    return mount(UserName, { localVue, mocks })
+  }
+
+  describe('mount', () => {
+    beforeEach(() => {
+      wrapper = Wrapper()
+    })
+
+    it('renders the component', () => {
+      expect(wrapper.find('div#username_form').exists()).toBeTruthy()
+    })
+
+    it('has an edit icon', () => {
+      expect(wrapper.find('svg.bi-pencil').exists()).toBeTruthy()
+    })
+
+    it('renders the username', () => {
+      expect(wrapper.findAll('div.col').at(2).text()).toBe('peter')
+    })
+
+    describe('edit username', () => {
+      beforeEach(async () => {
+        await wrapper.find('svg.bi-pencil').trigger('click')
+      })
+
+      it('shows an cancel icon', () => {
+        expect(wrapper.find('svg.bi-x-circle').exists()).toBeTruthy()
+      })
+
+      it('closes the input when cancel icon is clicked', async () => {
+        await wrapper.find('svg.bi-x-circle').trigger('click')
+        expect(wrapper.find('input').exists()).toBeFalsy()
+      })
+
+      it('does not change the username when cancel is clicked', async () => {
+        await wrapper.find('input').setValue('petra')
+        await wrapper.find('svg.bi-x-circle').trigger('click')
+        expect(wrapper.findAll('div.col').at(2).text()).toBe('peter')
+      })
+
+      it('has a submit button', () => {
+        expect(wrapper.find('button[type="submit"]').exists()).toBeTruthy()
+      })
+
+      it('does not enable submit button when data is not changed', async () => {
+        await wrapper.find('form').trigger('keyup')
+        expect(wrapper.find('button[type="submit"]').attributes('disabled')).toBe('disabled')
+      })
+
+      describe('successfull submit', () => {
+        beforeEach(async () => {
+          mockAPIcall.mockResolvedValue({
+            data: {
+              updateUserInfos: {
+                validValues: 3,
+              },
+            },
+          })
+          jest.clearAllMocks()
+          await wrapper.find('input').setValue('petra')
+          await wrapper.find('form').trigger('keyup')
+          await wrapper.find('button[type="submit"]').trigger('click')
+          await flushPromises()
+        })
+
+        it('calls the API', () => {
+          expect(mockAPIcall).toBeCalledWith(
+            expect.objectContaining({
+              variables: {
+                alias: 'petra',
+              },
+            }),
+          )
+        })
+
+        it('commits username to store', () => {
+          expect(storeCommitMock).toBeCalledWith('username', 'petra')
+        })
+
+        it('toasts a success message', () => {
+          expect(toastSuccessSpy).toBeCalledWith('settings.username.change-success')
+        })
+
+        it('has an edit button again', () => {
+          expect(wrapper.find('svg.bi-pencil').exists()).toBeTruthy()
+        })
+      })
+
+      describe('submit results in server error', () => {
+        beforeEach(async () => {
+          mockAPIcall.mockRejectedValue({
+            message: 'Error',
+          })
+          jest.clearAllMocks()
+          await wrapper.find('input').setValue('petra')
+          await wrapper.find('form').trigger('keyup')
+          await wrapper.find('button[type="submit"]').trigger('click')
+          await flushPromises()
+        })
+
+        it('calls the API', () => {
+          expect(mockAPIcall).toBeCalledWith(
+            expect.objectContaining({
+              variables: {
+                alias: 'petra',
+              },
+            }),
+          )
+        })
+
+        it('toasts an error message', () => {
+          expect(toastErrorSpy).toBeCalledWith('Error')
+        })
+      })
+    })
+
+    describe('no username in store', () => {
+      beforeEach(() => {
+        mocks.$store.state.username = null
+        wrapper = Wrapper()
+      })
+
+      it('displays an information why to enter a username', () => {
+        expect(wrapper.findAll('div.col').at(2).text()).toBe('settings.username.no-username')
+      })
+    })
+  })
+})
diff --git a/frontend/src/components/UserSettings/UserName.vue b/frontend/src/components/UserSettings/UserName.vue
new file mode 100644
index 000000000..4fc1b2f3a
--- /dev/null
+++ b/frontend/src/components/UserSettings/UserName.vue
@@ -0,0 +1,130 @@
+<template>
+  <b-card id="username_form" class="card-border-radius card-background-gray">
+    <div>
+      <b-row class="mb-4 text-right">
+        <b-col class="text-right">
+          <a
+            class="cursor-pointer"
+            @click="showUserData ? (showUserData = !showUserData) : cancelEdit()"
+          >
+            <span class="pointer mr-3">{{ $t('settings.username.change-username') }}</span>
+            <b-icon v-if="showUserData" class="pointer ml-3" icon="pencil"></b-icon>
+            <b-icon v-else icon="x-circle" class="pointer ml-3" variant="danger"></b-icon>
+          </a>
+        </b-col>
+      </b-row>
+    </div>
+
+    <div>
+      <validation-observer ref="usernameObserver" v-slot="{ handleSubmit, invalid }">
+        <b-form @submit.stop.prevent="handleSubmit(onSubmit)">
+          <b-row class="mb-3">
+            <b-col class="col-12">
+              <small>
+                <b>{{ $t('form.username') }}</b>
+              </small>
+            </b-col>
+            <b-col v-if="showUserData" class="col-12">
+              <span v-if="username">
+                {{ username }}
+              </span>
+              <div v-else class="alert">
+                {{ $t('settings.username.no-username') }}
+              </div>
+            </b-col>
+            <b-col v-else class="col-12">
+              <input-username
+                v-model="username"
+                :name="$t('form.username')"
+                :placeholder="$t('form.username-placeholder')"
+                :showAllErrors="true"
+                :unique="true"
+                :rules="rules"
+              />
+            </b-col>
+          </b-row>
+          <b-row class="text-right" v-if="!showUserData">
+            <b-col>
+              <div class="text-right" ref="submitButton">
+                <b-button
+                  :variant="disabled(invalid) ? 'light' : 'success'"
+                  @click="onSubmit"
+                  type="submit"
+                  :disabled="disabled(invalid)"
+                >
+                  {{ $t('form.save') }}
+                </b-button>
+              </div>
+            </b-col>
+          </b-row>
+        </b-form>
+      </validation-observer>
+    </div>
+  </b-card>
+</template>
+<script>
+import { updateUserInfos } from '@/graphql/mutations'
+import InputUsername from '@/components/Inputs/InputUsername'
+
+export default {
+  name: 'UserName',
+  components: {
+    InputUsername,
+  },
+  data() {
+    return {
+      showUserData: true,
+      username: this.$store.state.username || '',
+      usernameUnique: false,
+      rules: {
+        required: true,
+        min: 3,
+        max: 20,
+        usernameAllowedChars: true,
+        usernameHyphens: true,
+        usernameUnique: true,
+      },
+    }
+  },
+  methods: {
+    cancelEdit() {
+      this.username = this.$store.state.username || ''
+      this.showUserData = true
+    },
+    async onSubmit(event) {
+      event.preventDefault()
+      this.$apollo
+        .mutate({
+          mutation: updateUserInfos,
+          variables: {
+            alias: this.username,
+          },
+        })
+        .then(() => {
+          this.$store.commit('username', this.username)
+          this.showUserData = true
+          this.toastSuccess(this.$t('settings.username.change-success'))
+        })
+        .catch((error) => {
+          this.toastError(error.message)
+        })
+    },
+    disabled(invalid) {
+      return !this.newUsername || invalid
+    },
+  },
+  computed: {
+    newUsername() {
+      return this.username !== this.$store.state.username
+    },
+  },
+}
+</script>
+<style>
+.cursor-pointer {
+  cursor: pointer;
+}
+div.alert {
+  color: red;
+}
+</style>
diff --git a/frontend/src/graphql/mutations.js b/frontend/src/graphql/mutations.js
index 802ea1818..8a281aad9 100644
--- a/frontend/src/graphql/mutations.js
+++ b/frontend/src/graphql/mutations.js
@@ -26,6 +26,7 @@ export const forgotPassword = gql`
 
 export const updateUserInfos = gql`
   mutation(
+    $alias: String
     $firstName: String
     $lastName: String
     $password: String
@@ -35,6 +36,7 @@ export const updateUserInfos = gql`
     $hideAmountGDT: Boolean
   ) {
     updateUserInfos(
+      alias: $alias
       firstName: $firstName
       lastName: $lastName
       password: $password
@@ -145,6 +147,7 @@ export const login = gql`
   mutation($email: String!, $password: String!, $publisherId: Int) {
     login(email: $email, password: $password, publisherId: $publisherId) {
       gradidoID
+      alias
       firstName
       lastName
       language
diff --git a/frontend/src/graphql/queries.js b/frontend/src/graphql/queries.js
index a21117ac2..f254b93cc 100644
--- a/frontend/src/graphql/queries.js
+++ b/frontend/src/graphql/queries.js
@@ -89,6 +89,12 @@ export const queryOptIn = gql`
   }
 `
 
+export const checkUsername = gql`
+  query($username: String!) {
+    checkUsername(username: $username)
+  }
+`
+
 export const queryTransactionLink = gql`
   query($code: String!) {
     queryTransactionLink(code: $code) {
diff --git a/frontend/src/locales/de.json b/frontend/src/locales/de.json
index 8f02812ec..a29069104 100644
--- a/frontend/src/locales/de.json
+++ b/frontend/src/locales/de.json
@@ -167,12 +167,15 @@
     "thx": "Danke",
     "to": "bis",
     "to1": "an",
+    "username": "Nutzername",
+    "username-placeholder": "Gebe einen eindeutigen Nutzernamen ein",
     "validation": {
       "gddCreationTime": "Das Feld {_field_} muss eine Zahl zwischen {min} und {max} mit höchstens einer Nachkommastelle sein",
       "gddSendAmount": "Das Feld {_field_} muss eine Zahl zwischen {min} und {max} mit höchstens zwei Nachkommastellen sein",
       "is-not": "Du kannst dir selbst keine Gradidos überweisen",
-      "usernmae-regex": "Der Username muss mit einem Buchstaben beginnen, auf den mindestens zwei alpha-numerische Zeichen folgen müssen.",
-      "usernmae-unique": "Der Username ist bereits vergeben."
+      "username-allowed-chars": "Der Nutzername darf nur aus Buchstaben (ohne Umlaute), Zahlen, Binde- oder Unterstrichen bestehen.",
+      "username-hyphens": "Binde- oder Unterstriche müssen zwischen Buchstaben oder Zahlen stehen.",
+      "username-unique": "Der Nutzername ist bereits vergeben."
     },
     "your_amount": "Dein Betrag"
   },
@@ -320,7 +323,12 @@
       "subtitle": "Wenn du dein Passwort vergessen hast, kannst du es hier zurücksetzen."
     },
     "showAmountGDD": "Dein GDD Betrag ist sichtbar.",
-    "showAmountGDT": "Dein GDT Betrag ist sichtbar."
+    "showAmountGDT": "Dein GDT Betrag ist sichtbar.",
+    "username": {
+      "change-success": "Dein Nutzername wurde erfolgreich geändert.",
+      "change-username": "Nutzername ändern",
+      "no-username": "Bitte gebe einen Nutzernamen ein. Damit hilfst du anderen Benutzern dich zu finden, ohne deine Email preisgeben zu müssen."
+    }
   },
   "signin": "Anmelden",
   "signup": "Registrieren",
diff --git a/frontend/src/locales/en.json b/frontend/src/locales/en.json
index 2973150f9..ad7077e69 100644
--- a/frontend/src/locales/en.json
+++ b/frontend/src/locales/en.json
@@ -167,12 +167,15 @@
     "thx": "Thank you",
     "to": "to",
     "to1": "to",
+    "username": "Username",
+    "username-placeholder": "Enter a unique username",
     "validation": {
       "gddCreationTime": "The field {_field_} must be a number between {min} and {max} with at most one decimal place.",
       "gddSendAmount": "The {_field_} field must be a number between {min} and {max} with at most two digits after the decimal point",
       "is-not": "You cannot send Gradidos to yourself",
-      "usernmae-regex": "The username must start with a letter, followed by at least two alphanumeric characters.",
-      "usernmae-unique": "This username is already taken."
+      "username-allowed-chars": "The username may only contain letters, numbers, hyphens or underscores.",
+      "username-hyphens": "Hyphens or underscores must be in between letters or numbers.",
+      "username-unique": "This username is already taken."
     },
     "your_amount": "Your amount"
   },
@@ -320,7 +323,12 @@
       "subtitle": "If you have forgotten your password, you can reset it here."
     },
     "showAmountGDD": "Your GDD amount is visible.",
-    "showAmountGDT": "Your GDT amount is visible."
+    "showAmountGDT": "Your GDT amount is visible.",
+    "username": {
+      "change-success": "Your username has been changed successfully.",
+      "change-username": "Change username",
+      "no-username": "Please enter a username. This helps other users to find you without exposing your email."
+    }
   },
   "signin": "Sign in",
   "signup": "Sign up",
diff --git a/frontend/src/main.js b/frontend/src/main.js
index 4809e490c..f31311ab2 100755
--- a/frontend/src/main.js
+++ b/frontend/src/main.js
@@ -27,7 +27,7 @@ const filters = loadFilters(i18n)
 Vue.filter('amount', filters.amount)
 Vue.filter('GDD', filters.GDD)
 
-loadAllRules(i18n)
+loadAllRules(i18n, apolloProvider.defaultClient)
 
 addNavigationGuards(router, store, apolloProvider.defaultClient)
 
diff --git a/frontend/src/pages/Settings.vue b/frontend/src/pages/Settings.vue
index 530484d9a..c5ca00f08 100644
--- a/frontend/src/pages/Settings.vue
+++ b/frontend/src/pages/Settings.vue
@@ -3,6 +3,8 @@
     <user-card :balance="balance" :transactionCount="transactionCount"></user-card>
     <user-data />
     <hr />
+    <user-name />
+    <hr />
     <user-password />
     <hr />
     <user-language />
@@ -13,6 +15,7 @@
 <script>
 import UserCard from '@/components/UserSettings/UserCard'
 import UserData from '@/components/UserSettings/UserData'
+import UserName from '@/components/UserSettings/UserName'
 import UserPassword from '@/components/UserSettings/UserPassword'
 import UserLanguage from '@/components/UserSettings/UserLanguage'
 import UserNewsletter from '@/components/UserSettings/UserNewsletter'
@@ -22,6 +25,7 @@ export default {
   components: {
     UserCard,
     UserData,
+    UserName,
     UserPassword,
     UserLanguage,
     UserNewsletter,
diff --git a/frontend/src/store/store.js b/frontend/src/store/store.js
index f4fea20b7..7716d00de 100644
--- a/frontend/src/store/store.js
+++ b/frontend/src/store/store.js
@@ -16,9 +16,9 @@ export const mutations = {
   gradidoID: (state, gradidoID) => {
     state.gradidoID = gradidoID
   },
-  // username: (state, username) => {
-  //   state.username = username
-  // },
+  username: (state, username) => {
+    state.username = username
+  },
   firstName: (state, firstName) => {
     state.firstName = firstName
   },
@@ -59,7 +59,7 @@ export const actions = {
   login: ({ dispatch, commit }, data) => {
     commit('gradidoID', data.gradidoID)
     commit('language', data.language)
-    // commit('username', data.username)
+    commit('username', data.alias)
     commit('firstName', data.firstName)
     commit('lastName', data.lastName)
     commit('newsletterState', data.klickTipp.newsletterState)
@@ -71,7 +71,7 @@ export const actions = {
   },
   logout: ({ commit, state }) => {
     commit('token', null)
-    // commit('username', '')
+    commit('username', '')
     commit('gradidoID', null)
     commit('firstName', '')
     commit('lastName', '')
diff --git a/frontend/src/store/store.test.js b/frontend/src/store/store.test.js
index cc4d6a284..116594e77 100644
--- a/frontend/src/store/store.test.js
+++ b/frontend/src/store/store.test.js
@@ -26,6 +26,7 @@ const {
   token,
   firstName,
   lastName,
+  username,
   newsletterState,
   publisherId,
   isAdmin,
@@ -104,6 +105,14 @@ describe('Vuex store', () => {
       })
     })
 
+    describe('username', () => {
+      it('sets the state of username', () => {
+        const state = { username: null }
+        username(state, 'peter')
+        expect(state.username).toEqual('peter')
+      })
+    })
+
     describe('newsletterState', () => {
       it('sets the state of newsletterState', () => {
         const state = { newsletterState: null }
@@ -166,6 +175,7 @@ describe('Vuex store', () => {
       const commitedData = {
         gradidoID: 'my-gradido-id',
         language: 'de',
+        alias: 'peter',
         firstName: 'Peter',
         lastName: 'Lustig',
         klickTipp: {
@@ -180,7 +190,7 @@ describe('Vuex store', () => {
 
       it('calls eleven commits', () => {
         login({ commit, state }, commitedData)
-        expect(commit).toHaveBeenCalledTimes(10)
+        expect(commit).toHaveBeenCalledTimes(11)
       })
 
       it('commits gradidoID', () => {
@@ -193,44 +203,49 @@ describe('Vuex store', () => {
         expect(commit).toHaveBeenNthCalledWith(2, 'language', 'de')
       })
 
+      it('commits username', () => {
+        login({ commit, state }, commitedData)
+        expect(commit).toHaveBeenNthCalledWith(3, 'username', 'peter')
+      })
+
       it('commits firstName', () => {
         login({ commit, state }, commitedData)
-        expect(commit).toHaveBeenNthCalledWith(3, 'firstName', 'Peter')
+        expect(commit).toHaveBeenNthCalledWith(4, 'firstName', 'Peter')
       })
 
       it('commits lastName', () => {
         login({ commit, state }, commitedData)
-        expect(commit).toHaveBeenNthCalledWith(4, 'lastName', 'Lustig')
+        expect(commit).toHaveBeenNthCalledWith(5, 'lastName', 'Lustig')
       })
 
       it('commits newsletterState', () => {
         login({ commit, state }, commitedData)
-        expect(commit).toHaveBeenNthCalledWith(5, 'newsletterState', true)
+        expect(commit).toHaveBeenNthCalledWith(6, 'newsletterState', true)
       })
 
       it('commits hasElopage', () => {
         login({ commit, state }, commitedData)
-        expect(commit).toHaveBeenNthCalledWith(6, 'hasElopage', false)
+        expect(commit).toHaveBeenNthCalledWith(7, 'hasElopage', false)
       })
 
       it('commits publisherId', () => {
         login({ commit, state }, commitedData)
-        expect(commit).toHaveBeenNthCalledWith(7, 'publisherId', 1234)
+        expect(commit).toHaveBeenNthCalledWith(8, 'publisherId', 1234)
       })
 
       it('commits isAdmin', () => {
         login({ commit, state }, commitedData)
-        expect(commit).toHaveBeenNthCalledWith(8, 'isAdmin', true)
+        expect(commit).toHaveBeenNthCalledWith(9, 'isAdmin', true)
       })
 
       it('commits hideAmountGDD', () => {
         login({ commit, state }, commitedData)
-        expect(commit).toHaveBeenNthCalledWith(9, 'hideAmountGDD', false)
+        expect(commit).toHaveBeenNthCalledWith(10, 'hideAmountGDD', false)
       })
 
       it('commits hideAmountGDT', () => {
         login({ commit, state }, commitedData)
-        expect(commit).toHaveBeenNthCalledWith(10, 'hideAmountGDT', true)
+        expect(commit).toHaveBeenNthCalledWith(11, 'hideAmountGDT', true)
       })
     })
 
@@ -240,7 +255,7 @@ describe('Vuex store', () => {
 
       it('calls eleven commits', () => {
         logout({ commit, state })
-        expect(commit).toHaveBeenCalledTimes(10)
+        expect(commit).toHaveBeenCalledTimes(11)
       })
 
       it('commits token', () => {
@@ -248,49 +263,54 @@ describe('Vuex store', () => {
         expect(commit).toHaveBeenNthCalledWith(1, 'token', null)
       })
 
+      it('commits username', () => {
+        logout({ commit, state })
+        expect(commit).toHaveBeenNthCalledWith(2, 'username', '')
+      })
+
       it('commits gradidoID', () => {
         logout({ commit, state })
-        expect(commit).toHaveBeenNthCalledWith(2, 'gradidoID', null)
+        expect(commit).toHaveBeenNthCalledWith(3, 'gradidoID', null)
       })
 
       it('commits firstName', () => {
         logout({ commit, state })
-        expect(commit).toHaveBeenNthCalledWith(3, 'firstName', '')
+        expect(commit).toHaveBeenNthCalledWith(4, 'firstName', '')
       })
 
       it('commits lastName', () => {
         logout({ commit, state })
-        expect(commit).toHaveBeenNthCalledWith(4, 'lastName', '')
+        expect(commit).toHaveBeenNthCalledWith(5, 'lastName', '')
       })
 
       it('commits newsletterState', () => {
         logout({ commit, state })
-        expect(commit).toHaveBeenNthCalledWith(5, 'newsletterState', null)
+        expect(commit).toHaveBeenNthCalledWith(6, 'newsletterState', null)
       })
 
       it('commits hasElopage', () => {
         logout({ commit, state })
-        expect(commit).toHaveBeenNthCalledWith(6, 'hasElopage', false)
+        expect(commit).toHaveBeenNthCalledWith(7, 'hasElopage', false)
       })
 
       it('commits publisherId', () => {
         logout({ commit, state })
-        expect(commit).toHaveBeenNthCalledWith(7, 'publisherId', null)
+        expect(commit).toHaveBeenNthCalledWith(8, 'publisherId', null)
       })
 
       it('commits isAdmin', () => {
         logout({ commit, state })
-        expect(commit).toHaveBeenNthCalledWith(8, 'isAdmin', false)
+        expect(commit).toHaveBeenNthCalledWith(9, 'isAdmin', false)
       })
 
       it('commits hideAmountGDD', () => {
         logout({ commit, state })
-        expect(commit).toHaveBeenNthCalledWith(9, 'hideAmountGDD', false)
+        expect(commit).toHaveBeenNthCalledWith(10, 'hideAmountGDD', false)
       })
 
       it('commits hideAmountGDT', () => {
         logout({ commit, state })
-        expect(commit).toHaveBeenNthCalledWith(10, 'hideAmountGDT', true)
+        expect(commit).toHaveBeenNthCalledWith(11, 'hideAmountGDT', true)
       })
       // how to get this working?
       it.skip('calls localStorage.clear()', () => {
diff --git a/frontend/src/validation-rules.js b/frontend/src/validation-rules.js
index abb89b59f..124ef8528 100644
--- a/frontend/src/validation-rules.js
+++ b/frontend/src/validation-rules.js
@@ -1,8 +1,9 @@
 import { configure, extend } from 'vee-validate'
 // eslint-disable-next-line camelcase
 import { required, email, min, max, is_not } from 'vee-validate/dist/rules'
+import { checkUsername } from '@/graphql/queries'
 
-export const loadAllRules = (i18nCallback) => {
+export const loadAllRules = (i18nCallback, apollo) => {
   configure({
     defaultMessage: (field, values) => {
       // eslint-disable-next-line @intlify/vue-i18n/no-dynamic-keys
@@ -96,7 +97,7 @@ export const loadAllRules = (i18nCallback) => {
     message: (_, values) => i18nCallback.t('site.signup.one_number', values),
   })
 
-  extend('atLeastEightCharactera', {
+  extend('atLeastEightCharacters', {
     validate(value) {
       return !!value.match(/.{8,}/)
     },
@@ -123,4 +124,35 @@ export const loadAllRules = (i18nCallback) => {
     },
     message: (_, values) => i18nCallback.t('site.signup.dont_match', values),
   })
+
+  extend('usernameAllowedChars', {
+    validate(value) {
+      return !!value.match(/^[a-zA-Z0-9_-]+$/)
+    },
+    message: (_, values) => i18nCallback.t('form.validation.username-allowed-chars', values),
+  })
+
+  extend('usernameHyphens', {
+    validate(value) {
+      return !!value.match(/^[a-zA-Z0-9]+(?:[_-][a-zA-Z0-9]+?)*$/)
+    },
+    message: (_, values) => i18nCallback.t('form.validation.username-hyphens', values),
+  })
+
+  extend('usernameUnique', {
+    validate(value) {
+      if (!value.match(/^(?=.{3,20}$)[a-zA-Z0-9]+(?:[_-][a-zA-Z0-9]+?)*$/)) return true
+      return apollo
+        .query({
+          query: checkUsername,
+          variables: { username: value },
+        })
+        .then(({ data }) => {
+          return {
+            valid: data.checkUsername,
+          }
+        })
+    },
+    message: (_, values) => i18nCallback.t('form.validation.username-unique', values),
+  })
 }
diff --git a/frontend/test/testSetup.js b/frontend/test/testSetup.js
index 9e844370f..347a6be4a 100644
--- a/frontend/test/testSetup.js
+++ b/frontend/test/testSetup.js
@@ -34,7 +34,7 @@ const i18nMock = {
   n: (value, format) => value,
 }
 
-loadAllRules(i18nMock)
+loadAllRules(i18nMock, { query: jest.fn().mockResolvedValue({ data: { checkUsername: true } }) })
 
 global.localVue = createLocalVue()