Where to go looking
On a TIE the reference opens with the letter E trailed by a run of digits — think E00000000 — and you will spot it printed on the front or the reverse of the card.
On the green European certificate it appears as the IXESP, sometimes called the C-number. On the older A4 version it may instead be flagged as "Nº de soporte" somewhere near the top of the sheet.
What it unlocks
Digital services lean on it to confirm you really are who you claim — Cl@ve, the national immigration portal and a long list of regional administration sites among them. Leave the field blank and the online procedure simply will not advance.
In Palma
From Portixol to Son Espanyolet, newcomers rely on us for the the número de soporte in Palma. We prepare every document to the Oficina de Extranjería de Illes Balears (Palma) standard so nothing gets sent back.