diff --git a/backend/src/models/User.js b/backend/src/models/User.js
index 72cef4093..4bab080ca 100644
--- a/backend/src/models/User.js
+++ b/backend/src/models/User.js
@@ -4,7 +4,7 @@ module.exports = {
   id: { type: 'string', primary: true, default: uuid }, // TODO: should be type: 'uuid' but simplified for our tests
   actorId: { type: 'string', allow: [null] },
   name: { type: 'string', disallow: [null], min: 3 },
-  slug: 'string',
+  slug: { type: 'string', regex: /^[a-z0-9_-]+$/, lowercase: true },
   encryptedPassword: 'string',
   avatar: { type: 'string', allow: [null] },
   coverImg: { type: 'string', allow: [null] },
diff --git a/backend/src/models/User.spec.js b/backend/src/models/User.spec.js
index e00136970..7c4a26c55 100644
--- a/backend/src/models/User.spec.js
+++ b/backend/src/models/User.spec.js
@@ -18,3 +18,67 @@ describe('role', () => {
     )
   })
 })
+
+describe('slug', () => {
+  it('normalizes to lowercase letters', async () => {
+    const user = await instance.create('User', { slug: 'Matt' })
+    await expect(user.toJson()).resolves.toEqual(
+      expect.objectContaining({
+        slug: 'matt',
+      }),
+    )
+  })
+
+  it('must be unique', async done => {
+    await instance.create('User', { slug: 'Matt' })
+    try {
+      await expect(instance.create('User', { slug: 'Matt' })).rejects.toThrow('already exists')
+      done()
+    } catch (error) {
+      throw new Error(`
+        ${error}
+
+        Probably your database has no unique constraints!
+
+        To see all constraints go to http://localhost:7474/browser/ and
+        paste the following:
+        \`\`\`
+          CALL db.constraints();
+        \`\`\`
+
+        Learn how to setup the database here:
+        https://docs.human-connection.org/human-connection/neo4j
+      `)
+    }
+  })
+
+  describe('characters', () => {
+    const createUser = attrs => {
+      return instance.create('User', attrs).then(user => user.toJson())
+    }
+
+    it('-', async () => {
+      await expect(createUser({ slug: 'matt-rider' })).resolves.toMatchObject({
+        slug: 'matt-rider',
+      })
+    })
+
+    it('_', async () => {
+      await expect(createUser({ slug: 'matt_rider' })).resolves.toMatchObject({
+        slug: 'matt_rider',
+      })
+    })
+
+    it(' ', async () => {
+      await expect(createUser({ slug: 'matt rider' })).rejects.toThrow(
+        /fails to match the required pattern/,
+      )
+    })
+
+    it('ä', async () => {
+      await expect(createUser({ slug: 'mätt' })).rejects.toThrow(
+        /fails to match the required pattern/,
+      )
+    })
+  })
+})
diff --git a/cypress/integration/common/settings.js b/cypress/integration/common/settings.js
index b32924f6a..563d6a733 100644
--- a/cypress/integration/common/settings.js
+++ b/cypress/integration/common/settings.js
@@ -18,6 +18,8 @@ When('I save {string} as my new name', name => {
   cy.get('[type=submit]')
     .click()
     .not('[disabled]')
+  cy.get('.iziToast-message')
+    .should('contain', 'Your data was successfully updated')
 })
 
 When('I save {string} as my location', location => {
@@ -28,6 +30,8 @@ When('I save {string} as my location', location => {
   cy.get('[type=submit]')
     .click()
     .not('[disabled]')
+  cy.get('.iziToast-message')
+    .should('contain', 'Your data was successfully updated')
   myLocation = location
 })
 
@@ -38,6 +42,8 @@ When('I have the following self-description:', text => {
   cy.get('[type=submit]')
     .click()
     .not('[disabled]')
+  cy.get('.iziToast-message')
+    .should('contain', 'Your data was successfully updated')
   aboutMeText = text
 })
 
diff --git a/webapp/components/utils/UniqueSlugForm.js b/webapp/components/utils/UniqueSlugForm.js
new file mode 100644
index 000000000..c363fa608
--- /dev/null
+++ b/webapp/components/utils/UniqueSlugForm.js
@@ -0,0 +1,36 @@
+import { debounce } from 'lodash'
+import { checkSlugAvailableQuery } from '~/graphql/User.js'
+
+export default function UniqueSlugForm({ translate, apollo, currentUser }) {
+  return {
+    formSchema: {
+      slug: [
+        {
+          type: 'string',
+          required: true,
+          pattern: /^[a-z0-9_-]+$/,
+          message: translate('settings.validation.slug.regex'),
+        },
+        {
+          asyncValidator(rule, value, callback) {
+            debounce(() => {
+              const variables = { slug: value }
+              apollo.query({ query: checkSlugAvailableQuery, variables }).then(response => {
+                const {
+                  data: { User },
+                } = response
+                const existingSlug = User && User[0] && User[0].slug
+                const available = !existingSlug || existingSlug === currentUser.slug
+                if (!available) {
+                  callback(new Error(translate('settings.validation.slug.alreadyTaken')))
+                } else {
+                  callback()
+                }
+              })
+            }, 500)()
+          },
+        },
+      ],
+    },
+  }
+}
diff --git a/webapp/components/utils/UniqueSlugForm.spec.js b/webapp/components/utils/UniqueSlugForm.spec.js
new file mode 100644
index 000000000..de0e3fee6
--- /dev/null
+++ b/webapp/components/utils/UniqueSlugForm.spec.js
@@ -0,0 +1,80 @@
+import UniqueSlugForm from './UniqueSlugForm'
+import Schema from 'async-validator'
+
+let translate
+let apollo
+let currentUser
+
+beforeEach(() => {
+  translate = jest.fn(() => 'Validation error')
+  apollo = {
+    query: jest.fn().mockResolvedValue({ data: { User: [] } }),
+  }
+  currentUser = null
+})
+
+describe('UniqueSlugForm', () => {
+  let validate = object => {
+    const { formSchema } = UniqueSlugForm({ translate, apollo, currentUser })
+    const validator = new Schema(formSchema)
+    return validator.validate(object, { suppressWarning: true }).catch(({ errors }) => {
+      throw new Error(errors[0].message)
+    })
+  }
+
+  describe('regex', () => {
+    describe('non URL-safe characters, e.g. whitespaces', () => {
+      it('rejects', async () => {
+        await expect(validate({ slug: 'uh oh' })).rejects.toThrow('Validation error')
+      })
+    })
+
+    describe('alphanumeric, hyphens or underscores', () => {
+      it('validates', async () => {
+        await expect(validate({ slug: '_all-right_' })).resolves.toBeUndefined()
+      })
+    })
+  })
+
+  describe('given a currentUser with a slug', () => {
+    beforeEach(() => {
+      currentUser = { slug: 'current-user' }
+    })
+
+    describe('backend returns no user for given slug', () => {
+      beforeEach(() => {
+        apollo.query.mockResolvedValue({
+          data: { User: [] },
+        })
+      })
+
+      it('validates', async () => {
+        await expect(validate({ slug: 'slug' })).resolves.toBeUndefined()
+      })
+    })
+
+    describe('backend returns user', () => {
+      let slug
+      beforeEach(() => {
+        slug = 'already-taken'
+        apollo.query.mockResolvedValue({
+          data: { User: [{ slug: 'already-taken' }] },
+        })
+      })
+
+      it('rejects', async () => {
+        await expect(validate({ slug: 'uh oh' })).rejects.toThrow('Validation error')
+      })
+
+      describe('but it is the current user', () => {
+        beforeEach(() => {
+          currentUser = { slug: 'already-taken' }
+        })
+
+        it('validates', async () => {
+          await expect(validate({ slug })).resolves.toBeUndefined()
+        })
+      })
+    })
+  })
+})
diff --git a/webapp/graphql/User.js b/webapp/graphql/User.js
index 27b3785ae..dbc1997af 100644
--- a/webapp/graphql/User.js
+++ b/webapp/graphql/User.js
@@ -134,3 +134,11 @@ export const unfollowUserMutation = i18n => {
     }
   `
 }
+
+export const checkSlugAvailableQuery = gql`
+  query($slug: String!) {
+    User(slug: $slug) {
+      slug
+    }
+  }
+`
diff --git a/webapp/locales/de.json b/webapp/locales/de.json
index 5b83821f5..a784cd5f7 100644
--- a/webapp/locales/de.json
+++ b/webapp/locales/de.json
@@ -151,11 +151,18 @@
     "data": {
       "name": "Deine Daten",
       "labelName": "Dein Name",
+      "labelSlug": "Dein eindeutiger Benutzername",
       "namePlaceholder": "Petra Lustig",
       "labelCity": "Deine Stadt oder Region",
       "labelBio": "Über dich",
       "success": "Deine Daten wurden erfolgreich aktualisiert!"
     },
+    "validation": {
+      "slug": {
+        "regex": "Es sind nur Kleinbuchstaben, Zahlen, Unterstriche oder Bindestriche erlaubt.",
+        "alreadyTaken": "Dieser Benutzername ist schon vergeben."
+      }
+    },
     "security": {
       "name": "Sicherheit",
       "change-password": {
diff --git a/webapp/locales/en.json b/webapp/locales/en.json
index 39220d318..502aedd67 100644
--- a/webapp/locales/en.json
+++ b/webapp/locales/en.json
@@ -152,11 +152,18 @@
     "data": {
       "name": "Your data",
       "labelName": "Your Name",
+      "labelSlug": "Your unique user name",
       "namePlaceholder": "Femanon Funny",
       "labelCity": "Your City or Region",
       "labelBio": "About You",
       "success": "Your data was successfully updated!"
     },
+    "validation": {
+      "slug": {
+        "regex": "Allowed characters are only lowercase letters, numbers, underscores and hyphens.",
+        "alreadyTaken": "This user name is already taken."
+      }
+    },
     "security": {
       "name": "Security",
       "change-password": {
diff --git a/webapp/package.json b/webapp/package.json
index adea8fd6d..c38b9e099 100644
--- a/webapp/package.json
+++ b/webapp/package.json
@@ -98,6 +98,7 @@
     "@vue/eslint-config-prettier": "~5.0.0",
     "@vue/server-test-utils": "~1.0.0-beta.29",
     "@vue/test-utils": "~1.0.0-beta.29",
+    "async-validator": "^3.1.0",
     "babel-core": "~7.0.0-bridge.0",
     "babel-eslint": "~10.0.3",
     "babel-jest": "~24.9.0",
diff --git a/webapp/pages/settings/index.spec.js b/webapp/pages/settings/index.spec.js
index f0eff0641..1040f2ad0 100644
--- a/webapp/pages/settings/index.spec.js
+++ b/webapp/pages/settings/index.spec.js
@@ -24,6 +24,7 @@ describe('index.vue', () => {
             data: {
               UpdateUser: {
                 id: 'u1',
+                slug: 'peter',
                 name: 'Peter',
                 locationName: 'Berlin',
                 about: 'Smth',
@@ -37,34 +38,67 @@ describe('index.vue', () => {
       },
     }
     getters = {
-      'auth/user': () => {
-        return {}
-      },
+      'auth/user': () => ({}),
     }
   })
 
   describe('mount', () => {
+    let options
     const Wrapper = () => {
       store = new Vuex.Store({
         getters,
       })
-      return mount(index, { store, mocks, localVue })
+      return mount(index, { store, mocks, localVue, ...options })
     }
 
+    beforeEach(() => {
+      options = {}
+    })
+
     it('renders', () => {
       expect(Wrapper().contains('div')).toBe(true)
     })
 
-    describe('given a new username and hitting submit', () => {
-      it('calls updateUser mutation', () => {
+    describe('given form validation errors', () => {
+      beforeEach(() => {
+        options = {
+          ...options,
+          computed: {
+            formSchema: () => ({
+              slug: [
+                (_rule, _value, callback) => {
+                  callback(new Error('Ouch!'))
+                },
+              ],
+            }),
+          },
+        }
+      })
+
+      it('cannot call updateUser mutation', () => {
         const wrapper = Wrapper()
-        const input = wrapper.find('#name')
-        const submitForm = wrapper.find('.ds-form')
 
-        input.setValue('Peter')
-        submitForm.trigger('submit')
+        wrapper.find('#name').setValue('Peter')
+        wrapper.find('.ds-form').trigger('submit')
 
-        expect(mocks.$apollo.mutate).toHaveBeenCalled()
+        expect(mocks.$apollo.mutate).not.toHaveBeenCalled()
+      })
+    })
+
+    describe('no form validation errors', () => {
+      beforeEach(() => {
+        options = { ...options, computed: { formSchema: () => ({}) } }
+      })
+
+      describe('given a new username and hitting submit', () => {
+        it('calls updateUser mutation', () => {
+          const wrapper = Wrapper()
+
+          wrapper.find('#name').setValue('Peter')
+          wrapper.find('.ds-form').trigger('submit')
+
+          expect(mocks.$apollo.mutate).toHaveBeenCalled()
+        })
       })
     })
   })
diff --git a/webapp/pages/settings/index.vue b/webapp/pages/settings/index.vue
index 5c99f4b8b..d32d9a91b 100644
--- a/webapp/pages/settings/index.vue
+++ b/webapp/pages/settings/index.vue
@@ -1,39 +1,49 @@
 <template>
-  <ds-form v-model="form" @submit="submit">
-    <ds-card :header="$t('settings.data.name')">
-      <ds-input
-        id="name"
-        model="name"
-        icon="user"
-        :label="$t('settings.data.labelName')"
-        :placeholder="$t('settings.data.namePlaceholder')"
-      />
-      <!-- eslint-disable vue/use-v-on-exact -->
-      <ds-select
-        id="city"
-        model="locationName"
-        icon="map-marker"
-        :options="cities"
-        :label="$t('settings.data.labelCity')"
-        :placeholder="$t('settings.data.labelCity')"
-        :loading="loadingGeo"
-        @input.native="handleCityInput"
-      />
-      <!-- eslint-enable vue/use-v-on-exact -->
-      <ds-input
-        id="bio"
-        model="about"
-        type="textarea"
-        rows="3"
-        :label="$t('settings.data.labelBio')"
-        :placeholder="$t('settings.data.labelBio')"
-      />
-      <template slot="footer">
-        <ds-button style="float: right;" icon="check" type="submit" :loading="loadingData" primary>
-          {{ $t('actions.save') }}
-        </ds-button>
-      </template>
-    </ds-card>
+  <ds-form v-model="form" :schema="formSchema" @submit="submit">
+    <template slot-scope="{ errors }">
+      <ds-card :header="$t('settings.data.name')">
+        <ds-input
+          id="name"
+          model="name"
+          icon="user"
+          :label="$t('settings.data.labelName')"
+          :placeholder="$t('settings.data.namePlaceholder')"
+        />
+        <ds-input id="slug" model="slug" icon="at" :label="$t('settings.data.labelSlug')" />
+        <!-- eslint-disable vue/use-v-on-exact -->
+        <ds-select
+          id="city"
+          model="locationName"
+          icon="map-marker"
+          :options="cities"
+          :label="$t('settings.data.labelCity')"
+          :placeholder="$t('settings.data.labelCity')"
+          :loading="loadingGeo"
+          @input.native="handleCityInput"
+        />
+        <!-- eslint-enable vue/use-v-on-exact -->
+        <ds-input
+          id="bio"
+          model="about"
+          type="textarea"
+          rows="3"
+          :label="$t('settings.data.labelBio')"
+          :placeholder="$t('settings.data.labelBio')"
+        />
+        <template slot="footer">
+          <ds-button
+            style="float: right;"
+            icon="check"
+            :disabled="errors"
+            type="submit"
+            :loading="loadingData"
+            primary
+          >
+            {{ $t('actions.save') }}
+          </ds-button>
+        </template>
+      </ds-card>
+    </template>
   </ds-form>
 </template>
 
@@ -42,6 +52,7 @@ import gql from 'graphql-tag'
 
 import { mapGetters, mapMutations } from 'vuex'
 import { CancelToken } from 'axios'
+import UniqueSlugForm from '~/components/utils/UniqueSlugForm'
 
 let timeout
 const mapboxToken = process.env.MAPBOX_TOKEN
@@ -60,9 +71,10 @@ const query = gql`
 */
 
 const mutation = gql`
-  mutation($id: ID!, $name: String, $locationName: String, $about: String) {
-    UpdateUser(id: $id, name: $name, locationName: $locationName, about: $about) {
+  mutation($id: ID!, $slug: String, $name: String, $locationName: String, $about: String) {
+    UpdateUser(id: $id, slug: $slug, name: $name, locationName: $locationName, about: $about) {
       id
+      slug
       name
       locationName
       about
@@ -84,10 +96,20 @@ export default {
     ...mapGetters({
       currentUser: 'auth/user',
     }),
+    formSchema() {
+      const uniqueSlugForm = UniqueSlugForm({
+        apollo: this.$apollo,
+        currentUser: this.currentUser,
+        translate: this.$t,
+      })
+      return {
+        ...uniqueSlugForm.formSchema,
+      }
+    },
     form: {
       get: function() {
-        const { name, locationName, about } = this.currentUser
-        return { name, locationName, about }
+        const { name, slug, locationName, about } = this.currentUser
+        return { name, slug, locationName, about }
       },
       set: function(formData) {
         this.formData = formData
@@ -100,7 +122,7 @@ export default {
     }),
     async submit() {
       this.loadingData = true
-      const { name, about } = this.formData
+      const { name, slug, about } = this.formData
       let { locationName } = this.formData || this.currentUser
       locationName = locationName && (locationName['label'] || locationName)
       try {
@@ -109,14 +131,16 @@ export default {
           variables: {
             id: this.currentUser.id,
             name,
+            slug,
             locationName,
             about,
           },
           update: (store, { data: { UpdateUser } }) => {
-            const { name, locationName, about } = UpdateUser
+            const { name, slug, locationName, about } = UpdateUser
             this.setCurrentUser({
               ...this.currentUser,
               name,
+              slug,
               locationName,
               about,
             })
diff --git a/webapp/yarn.lock b/webapp/yarn.lock
index ff2ba5dbe..a0d53d690 100644
--- a/webapp/yarn.lock
+++ b/webapp/yarn.lock
@@ -3661,6 +3661,11 @@ async-retry@^1.2.1:
   dependencies:
     retry "0.12.0"
 
+async-validator@^3.1.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/async-validator/-/async-validator-3.1.0.tgz#447db5eb003cbb47e650f040037a29fc3881ce92"
+  integrity sha512-XyAHGwtpx3Y3aHIOaGXXFo4tiulnrh+mXBU9INxig6Q8rtmtmBxDuCxb60j7EIGbAsQg9cxfJ2jrUZ+fIqEnBQ==
+
 async@^2.1.4:
   version "2.6.2"
   resolved "https://registry.yarnpkg.com/async/-/async-2.6.2.tgz#18330ea7e6e313887f5d2f2a904bac6fe4dd5381"