diff --git a/src/app.module.ts b/src/app.module.ts
index 5a7d70d..0de352c 100644
--- a/src/app.module.ts
+++ b/src/app.module.ts
@@ -10,6 +10,7 @@ import { PersonService } from "./controller/person/person.service";
 import { SubjectController } from "./controller/subject/subject.controller";
 import { SubjectService } from "./controller/subject/subject.service";
 import * as dotenv from "dotenv";
+import { MigratorController } from "./controller/migrator/migrator.controller";
 
 // Must be done before initializing DB.
 console.log(dotenv.config());
@@ -31,7 +32,7 @@ console.log(dotenv.config());
             synchronize: false,
         }),
     ],
-    controllers: [CertificateController, PersonController, SubjectController],
+    controllers: [CertificateController, PersonController, SubjectController, MigratorController],
     providers: [CertificateService, PersonService, SubjectService],
 })
 export class AppModule {}
diff --git a/src/controller/certificate/certificate.controller.ts b/src/controller/certificate/certificate.controller.ts
index bbd570a..0c27112 100644
--- a/src/controller/certificate/certificate.controller.ts
+++ b/src/controller/certificate/certificate.controller.ts
@@ -1,4 +1,4 @@
-import { Body, Controller, Delete, Get, InternalServerErrorException, Param, Post, Res, StreamableFile } from "@nestjs/common";
+import { Body, Controller, Delete, Get, InternalServerErrorException, Param, Post, Res } from "@nestjs/common";
 import { renderToString } from "solid-js/web";
 import { Certs } from "../../views/Certs";
 import { template } from "./certificate.template";
@@ -19,7 +19,7 @@ export class CertificateController {
     }
 
     @Get(":dni")
-    getByDni(@Param() param: {dni: string}) {
+    getByDni(@Param() param: { dni: string }) {
         return this.certificateService.getByDni(param.dni);
     }
 
@@ -30,7 +30,7 @@ export class CertificateController {
     }
 
     @Post("generate/:id")
-    async generate(@Param() param: {id: string}, @Res({ passthrough: true }) res: Response) {
+    async generate(@Param() param: { id: string }, @Res({ passthrough: true }) res: Response) {
         const [stream, filename] = await this.certificateService.generate(parseInt(param.id, 10));
 
         const str = res.writeHead(201, {
@@ -42,7 +42,7 @@ export class CertificateController {
     }
 
     @Delete(":id")
-    async delete(@Param() param: {id: number}) {
+    async delete(@Param() param: { id: number }) {
         console.log(param);
         const result = await this.certificateService.deleteById(param.id);
         if (!result) {
diff --git a/src/controller/migrator/migrator.controller.ts b/src/controller/migrator/migrator.controller.ts
new file mode 100644
index 0000000..b1a7d8c
--- /dev/null
+++ b/src/controller/migrator/migrator.controller.ts
@@ -0,0 +1,162 @@
+import { Controller, Get } from "@nestjs/common";
+import { CursoGIE } from "src/model/CursoGIE/cursoGIE.entity";
+import { Persona } from "src/model/Persona/persona.entity";
+import { RegistroGIE } from "src/model/RegistroGIE/registroGIE.entity";
+import { DataSource, Repository } from "typeorm";
+import { PersonService } from "../person/person.service";
+
+@Controller("migrator")
+export class MigratorController {
+    registroGIERepository: Repository<RegistroGIE>;
+    personGIERepository: Repository<Persona>;
+    subjectRepo: Repository<CursoGIE>;
+
+    constructor(dataSource: DataSource, private personService: PersonService) {
+        this.registroGIERepository = dataSource.getRepository(RegistroGIE);
+        this.personGIERepository = dataSource.getRepository(Persona);
+        this.subjectRepo = dataSource.getRepository(CursoGIE);
+    }
+
+    @Get()
+    async migrate() {
+        const registers = await this.registroGIERepository.find({
+            // @ts-ignore
+            select: {
+                cursoGIE: null,
+                persona: null,
+            },
+        });
+
+        // Try to create Persons for each user
+        for (const register of registers) {
+            const {curso, persona, cursoGIE, dni} = register;
+
+            // If this register doesn't link to a Person
+            if (!persona) {
+                // Try to get the person by DNI
+                try {
+                    await this.personService.getByDni(dni);
+
+                    // Update this register
+                    register.persona = (await this.personGIERepository.findOneBy({dni}))!;
+                } catch (e) {
+                    // Return creation form to the user
+                    return `
+                    <html>
+                    <body>
+                    <div class="p-2">
+                    <h2 class="my-2 font-medium text-xl">1.1 Registrar persona manualmente</h2>
+                    <h3>${register.nombre}</h3>
+                    <form id="form" class="px-4">
+                        <label for="add-person-dni">DNI</label>
+                        <br/>
+
+                        <label for="add-person-nombres">Nombres</label>
+                        <br/>
+                        <input
+                            id="add-person-nombres"
+                            name="add-person-nombres"
+                            class="bg-c-background text-c-on-background border-c-outline border-2 rounded px-2 py-1
+                                invalid:border-c-error invalid:text-c-error
+                                focus:border-c-primary outline-none
+                                disabled:opacity-50 disabled:cursor-not-allowed"
+                            type="text"
+                            placeholder="Nombres"
+                            required="true"
+                        />
+                        <br/>
+                        <br/>
+
+                        <div class="grid grid-cols-2 w-1/2">
+                            <div>
+                                <label for="add-person-apellido-paterno">Apellido Paterno</label>
+                                <br/>
+                                <input
+                                    id="add-person-apellido-paterno"
+                                    class="bg-c-background text-c-on-background border-c-outline border-2 rounded px-2 py-1
+                                invalid:border-c-error invalid:text-c-error
+                                focus:border-c-primary outline-none
+                                disabled:opacity-50 disabled:cursor-not-allowed"
+                                    type="text"
+                                    placeholder="Apellido paterno"
+                                />
+                            </div>
+                            <div>
+                                <label for="add-person-apellido-paterno">Apellido Materno</label>
+                                <br/>
+                                <input
+                                    id="add-person-apellido-materno"
+                                    class="bg-c-background text-c-on-background border-c-outline border-2 rounded px-2 py-1
+                                invalid:border-c-error invalid:text-c-error
+                                focus:border-c-primary outline-none
+                                disabled:opacity-50 disabled:cursor-not-allowed"
+                                    type="text"
+                                    placeholder="Apellido materno"
+                                />
+                            </div>
+                        </div>
+                        <br/>
+
+                        <input
+                            class="bg-c-primary text-c-on-primary px-4 py-2 rounded-md cursor-pointer
+                                disabled:opacity-50 disabled:cursor-not-allowed"
+                            type="submit"
+                            value="Registrar persona"
+                        />
+                    </form>
+
+                    <br/>
+
+                    <script>
+                    const form = document.getElementById("form");
+                    form.addEventListener("submit", async (ev) => {
+                        ev.preventDefault();
+
+                        const response = await fetch("/person", {
+                            method: "POST",
+                            headers: {
+                                "Content-Type": "application/json",
+                            },
+                            body: JSON.stringify({
+                                dni: "${dni}",
+                                apellidoPaterno: document.getElementById("add-person-apellido-paterno").value.toUpperCase().trim(),
+                                apellidoMaterno: document.getElementById("add-person-apellido-materno").value.toUpperCase().trim(),
+                                nombres: document.getElementById("add-person-nombres").value.toUpperCase().trim(),
+                            }),
+                        });
+                
+                        if (response.ok) {
+                            alert("OK");
+                            window.location.reload();
+                        } else {
+                            alert("Error creating");
+                        }
+                
+                    });
+                    </script>
+                </div>
+                    </body>
+                    </html>
+                    `;
+                    return `NOT FOUND IN DB NOR SUNAT: ${JSON.stringify(register)}`;
+                }
+            }
+
+            // If this register doesn't link to a Curso
+            if (!cursoGIE) {
+                // Get Curso and update
+                const cursoGIE = await this.subjectRepo.findOneBy({id: curso});
+
+                register.cursoGIE = cursoGIE!;
+            }
+
+            // Save person
+            if (!persona || !cursoGIE) {
+                await this.registroGIERepository.save(register);
+            }
+        }
+
+        return "All registers updated (?) :D";
+    }
+}
+
diff --git a/src/controller/person/person.service.ts b/src/controller/person/person.service.ts
index 788c4d4..4046ceb 100644
--- a/src/controller/person/person.service.ts
+++ b/src/controller/person/person.service.ts
@@ -15,7 +15,7 @@ interface SunatPerson {
 export class PersonService {
     personaRepository: Repository<Persona>;
 
-    constructor(private dataSource: DataSource) {
+    constructor(dataSource: DataSource) {
         this.personaRepository = dataSource.getRepository(Persona);
     }
 
diff --git a/src/model/RegistroGIE/registroGIE.entity.ts b/src/model/RegistroGIE/registroGIE.entity.ts
index d7adf05..1298d66 100644
--- a/src/model/RegistroGIE/registroGIE.entity.ts
+++ b/src/model/RegistroGIE/registroGIE.entity.ts
@@ -36,9 +36,9 @@ export class RegistroGIE {
 
     /* New fields */
 
-    @ManyToOne(() => Persona, (persona) => persona.registros)
+    @ManyToOne(() => Persona,(persona) => persona.registros, {nullable: true})
         persona: Persona;
 
-    @ManyToOne(() => CursoGIE)
+    @ManyToOne(() => CursoGIE, {nullable: true})
         cursoGIE: CursoGIE;
 }
diff --git a/src/views/components/Registers.tsx b/src/views/components/Registers.tsx
index c9affdb..04908f8 100644
--- a/src/views/components/Registers.tsx
+++ b/src/views/components/Registers.tsx
@@ -41,7 +41,7 @@ export function Registers(props: { person: Person | null, lastUpdate: number })
             <div class="px-4">
                 <Show when={props.person !== null}>
                     <span>Nombres y Apellidos</span>
-                    <br/>
+                    <br />
                     <input
                         type="text"
                         disabled
@@ -84,14 +84,14 @@ export function Registers(props: { person: Person | null, lastUpdate: number })
     );
 }
 
-function Register(props: {cert: RegisterReturn, onUpdate: () => void}) {
+function Register(props: { cert: RegisterReturn, onUpdate: () => void }) {
     const [deleteConfirmation, setDeleteConfirmation] = createSignal(false);
     const [deleteText, setDeleteText] = createSignal("Eliminar");
 
     const deleteRegister = async() => {
         if (deleteConfirmation()) {
             // Actually delete from DB
-            const response = await fetch(`/certificate/${props.cert.id}`,{
+            const response = await fetch(`/certificate/${props.cert.id}`, {
                 method: "DELETE",
             });
 
@@ -113,7 +113,7 @@ function Register(props: {cert: RegisterReturn, onUpdate: () => void}) {
     };
 
     const getCertificate = async() => {
-        const response = await fetch(`/certificate/generate/${props.cert.id}`,{
+        const response = await fetch(`/certificate/generate/${props.cert.id}`, {
             method: "POST",
         });
 
@@ -145,7 +145,8 @@ function Register(props: {cert: RegisterReturn, onUpdate: () => void}) {
             return;
 
         } else {
-            alert("Error downloading...");
+            const json = await response.json();
+            alert(json);
         }
     };
 
@@ -158,10 +159,10 @@ function Register(props: {cert: RegisterReturn, onUpdate: () => void}) {
                 <Show when={props.cert.generatable}>
                     <button
                         class="rounded-full py-1 px-2 shadow"
-                        style={{"background-color": "#0055d5", "color": "#ffffff"}}
+                        style={{ "background-color": "#0055d5", "color": "#ffffff" }}
                         onclick={getCertificate}
                     >
-                    DOCX
+                        DOCX
                     </button>
                 </Show>
             </td>