The British resident’s card, signal by signal
Six signals from a Briton settled by the Mar Menor before 2021 to the Agreement card: the date, the old paper, the fee, the booking, the folder, the card.

Since Brexit, British residents on this coast have one document to aim for: a TIE, the foreigner’s identity card, issued under the Withdrawal Agreement. Here is the way to it, one signal at a time, for someone who settled here before the end of 2020.
First signal: your date. The Agreement protects people who were living in Spain by the end of 2020. Gather what shows it: the old green certificate if you registered, a padrón (municipal register) certificate, a rental contract or deed, utility bills, Spanish bank statements from that time.
Second signal: the paper you already hold. With the green certificate issued to Europeans before Brexit, the card is an exchange, done at the police. Without it, your case is a first application: the Delegación del Gobierno’s instructions for the Oficina de Extranjería in Murcia list the Brexit residence forms, EX-20 for British nationals and EX-21 for their relatives. There, the proof of your date carries the whole file.
Third signal: the fee. Generate the Modelo 790 código 012 on the police’s electronic office, tick the box for your card and pay it at a bank or online. The amount appears when you tick; we never quote one, because it changes.
Fourth signal: the booking. In the cita previa for Murcia province, choose the police trámite for card issue, the fingerprint appointment. TIE issue appears on policia.es at the Comisaría de Cartagena, C/ Menéndez y Pelayo 6, and at the brigade in Murcia; accept the slot only once you have read the office on the screen.
Fifth signal: the folder. Your passport and a copy, a recent colour photograph, the green certificate or your proofs of residence, a recent padrón certificate, proof of the paid 790-012 and the confirmation. The officer takes your fingerprints and hands you a resguardo, the receipt that covers you until the card is ready.
Sixth signal: the card. Collect it in person, with the resguardo and your passport, from the office that took your prints. Check your name, the dates and the mention of the Agreement before you leave the desk, and note the expiry date for the renewal to come.