diff --git a/src/models/actions/CreateParticipant.ts b/src/models/actions/CreateParticipant.ts
index 00c8783..9cd51ce 100644
--- a/src/models/actions/CreateParticipant.ts
+++ b/src/models/actions/CreateParticipant.ts
@@ -1,5 +1,6 @@
 import { IsEmail, IsInt, IsNotEmpty, IsOptional, IsPhoneNumber, IsString } from 'class-validator';
 import { getConnectionManager } from 'typeorm';
+import { config } from '../../config';
 import { AddressNotFoundError, AddressWrongTypeError } from '../../errors/AddressErrors';
 import { Address } from '../entities/Address';
 
@@ -32,7 +33,7 @@ export abstract class CreateParticipant {
      */
     @IsString()
     @IsOptional()
-    @IsPhoneNumber("ZZ")
+    @IsPhoneNumber(config.phone_validation_countrycode)
     phone?: string;
 
     /**
diff --git a/src/models/actions/CreateUser.ts b/src/models/actions/CreateUser.ts
index ff6771a..d3c6ef6 100644
--- a/src/models/actions/CreateUser.ts
+++ b/src/models/actions/CreateUser.ts
@@ -2,6 +2,7 @@ import * as argon2 from "argon2";
 import { IsEmail, IsOptional, IsPhoneNumber, IsString } from 'class-validator';
 import { getConnectionManager } from 'typeorm';
 import * as uuid from 'uuid';
+import { config } from '../../config';
 import { UsernameOrEmailNeededError } from '../../errors/UserErrors';
 import { UserGroupNotFoundError } from '../../errors/UserGroupErrors';
 import { User } from '../entities/User';
@@ -49,7 +50,7 @@ export class CreateUser {
      * The new user's phone number.
      * Optional
      */
-    @IsPhoneNumber("ZZ")
+    @IsPhoneNumber(config.phone_validation_countrycode)
     @IsOptional()
     phone?: string;
 
diff --git a/src/models/entities/User.ts b/src/models/entities/User.ts
index 8e29e27..ebc62b1 100644
--- a/src/models/entities/User.ts
+++ b/src/models/entities/User.ts
@@ -1,5 +1,6 @@
 import { IsBoolean, IsEmail, IsInt, IsNotEmpty, IsOptional, IsPhoneNumber, IsString, IsUUID } from "class-validator";
 import { Column, Entity, JoinTable, ManyToMany, ManyToOne, OneToMany, PrimaryGeneratedColumn } from "typeorm";
+import { config } from '../../config';
 import { Permission } from './Permission';
 import { UserAction } from './UserAction';
 import { UserGroup } from './UserGroup';
@@ -35,7 +36,7 @@ export class User {
   */
   @Column({ nullable: true })
   @IsOptional()
-  @IsPhoneNumber("ZZ")
+  @IsPhoneNumber(config.phone_validation_countrycode)
   phone?: string;
 
   /**