> ## Documentation Index > Fetch the complete documentation index at: https://docs.melso.ai/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Melso MCP: https://mcp.melso.ai/mcp (OAuth; one company per connection). Documentation-search MCP: https://docs.melso.ai/mcp; it does not act on customer accounts. > > Use the live tool list and respect company membership. Ask the person to approve the exact invoice or tax return version in the signed-in app. Melso's professionals prepare and file included returns after approval; an AI assistant does not file. A prepared file or an approval is not evidence of filing: only the AEAT's reference and receipt are. Keep credentials out of chat and logs. # Invoicing > Save customers, prepare a draft, approve issuing it in the app, understand numbering and legal registration, correct an issued invoice and record a payment. **Facturas** (Invoices) opens **Facturas y cobros** (Invoices and payments). It has three tabs: **Facturas** (Invoices), **Presupuestos** (Quotes) and **Clientes** (Customers). Invoicing with Melso is optional. If you chose another program during setup, the section is hidden. You can switch it on under **Configuración**, with **Emitir facturas con Melso**. See [Setup and fiscal profile](/essentials/setup#edit-the-profile-later). ## Before your first invoice Issuing needs two things: 1. A complete fiscal profile. 2. The issuer authorization. Melso registers your invoices in the tax network that applies to you, and you authorize it once. The app shows **Autoriza al emisor para registrar tus facturas en la red fiscal correspondiente** with the button **Abrir autorización** (Open authorization). Until both are done, the page shows **Completa tus datos fiscales y la autorización del emisor** (Complete your fiscal details and the issuer authorization). ## Customers Add a customer with **Nuevo cliente** (New customer), from the **Clientes** tab or while you write an invoice. | Field | Notes | | - | - | | **Nombre** (Name) | Required. | | **Tipo de cliente** (Customer type) | Required. **Empresa** (company), **Profesional** (professional) or **Particular** (individual). | | **NIF** (Tax ID) | Required unless the customer is an individual. | | **Domicilio** (Address) | Postal address. | | **Email** | Where the issued invoice is sent. | Melso invoices customers in Spain. An invoice for a customer in another country is refused, because cross-border taxation needs a fiscal review first. Changing a customer never changes an invoice you already issued. An issued invoice keeps the customer details it was issued with. The one exception is the email address: delivery uses the customer's current email. ## Prepare a draft Start with **Nueva factura** (New invoice). Choose the customer and the **Tipo de documento** (Document type): * **Factura** (Invoice). * **Presupuesto / proforma** (Quote or pro forma). It cannot be issued. Edit it and choose **Factura** first. * **Rectificativa** (Corrective invoice). See [Correct an issued invoice](#correct-an-issued-invoice). Each line has a **Concepto** (description), **Cantidad** (quantity), **Precio unitario** (unit price), the tax rate and a **Tipo de línea** (line type): **Servicio** (service) or **Bien** (goods). * VAT rates are 21, 10, 4 or 0. A 0 rate needs its legal basis in the notes. * In the Canary Islands the invoice uses IGIC at 7. * IRPF withholding is set for the whole invoice: 0, 7 or 15. It applies when a professional invoices a company or another professional. A company's invoices carry no IRPF withholding. * Amounts are in euros. * An invoice to an individual with no tax ID is a simplified invoice. It cannot exceed 400 euros. A draft is saved without a number. Taxes and totals are calculated when you save. You can keep editing a draft until you issue it. ## Approve issuing in the app Open the draft and check the customer, the dates, the lines and the totals. Then choose **Emitir y enviar** (Issue and send). The app asks **¿Emitir esta factura?** and warns that a legal number will be assigned, the registered invoice will be sent, and you will not be able to edit it afterwards. Only the company's owner can issue an invoice, and only in the signed-in web app. A team member can prepare drafts. A WhatsApp message or an AI assistant cannot issue: they can prepare the draft and give you the link. Your approval applies to the exact draft you reviewed. If the draft or your fiscal profile changed after you opened it, issuing is refused and you review the current version. When you, the owner, issue the invoice in the app, it: 1. Assigns the next number in the series. 2. Registers the invoice in the tax network and stores the registered PDF with its QR code. 3. Emails the invoice to the customer, with the PDF attached. 4. Creates a payment link, if the company has online payments connected. If the email fails, the invoice is still issued. The invoice shows **Email enviado** (Email sent) or **Email aún no enviado** (Email not sent yet). Download the registered PDF with **Descargar PDF original** (Download original PDF). ### If registration does not finish The number stays reserved for that invoice. Retry the same invoice. Do not prepare a replacement. ## Numbering * The number is assigned when you issue, never before. * Numbers run in sequence inside a series. The default series is the year of the issue date, so an invoice shows as `2026-1`. * Corrective invoices have their own series, with the prefix `R-`, starting at 1. * The invoice series and the next invoice number are part of your [fiscal profile](/essentials/setup#what-the-fiscal-profile-holds). ## Legal registration Each invoice you issue is registered in the tax network for your tax territory: TicketBAI in Álava, Bizkaia and Gipuzkoa, and VeriFactu in the common territory and the Canary Islands. An invoice counts as registered when it is signed, has its QR code and has a valid PDF. That PDF is stored unchanged. The status line **Registro fiscal** (Fiscal registration) on the invoice shows where it is. ## Invoice states | State | Meaning | | - | - | | **Borrador** (Draft) | Saved without a number. You can edit it. | | **Pendiente** (Pending) | Issued and waiting for payment. | | **Enviada · pendiente** (Sent, pending) | Issued, sent to the customer and waiting for payment. | | **Vencida** (Overdue) | Issued or sent, and the due date has passed. | | **Cobrada** (Paid) | You recorded the payment. | | **Anulada** (Void) | The invoice is void. | ## Correct an issued invoice An issued invoice cannot be edited. To fix one, prepare a corrective invoice that refers to it. The original stays as it was. * Corrections work by differences. A negative unit price credits or cancels the original. A positive one increases the amount. * Only a registered invoice can be corrected. * The correction goes to the same customer as the original. * The reason for the correction is required in the notes. A corrective invoice starts as a draft. The owner reviews it and issues it like any other invoice. ## Record a payment When the customer has paid, choose **Marcar como cobrada** (Mark as paid). It records a full payment on an issued invoice. There are no partial payments. Recording a payment does not charge a card or move money. It notes money you already received. If the invoice had a payment link, the link is switched off. ## Limits that come from your plan Without an active plan you can still see and download your invoices, but you cannot create, edit, issue or mark them as paid. The app then shows **Tu plan no está activo: puedes ver y descargar tus datos, pero no añadir ni cambiar nada.** Plans include a monthly allowance of issued invoices. See [Plans and service scope](/essentials/plans) for where to check yours. ## With an AI assistant A connected assistant can find or save a customer, prepare the draft and give you the approval link. See [Use cases](/mcp/use-cases#draft-an-invoice-for-a-customer) and the [`invoices`](/mcp/tools/invoices) tool. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.