Constitutional and professional basis
Attorney-client privilege is grounded in Art. 24.2 CE (right to defence, confirmed by STC 228/2006) and Art. 5 CDAE 2019 (continuing obligation after retainer ends).
Key exceptions: AML (Law 10/2010): lawyers in real estate, company formation and fiduciary management must report to SEPBLAC; Art. 450 CP duty: resolved in favour of privilege except for imminent grave risk to life; Home searches: prior judicial authorisation required with Bar Dean present (STS 583/2017).
Breach consequences: Disciplinary sanction, civil liability (Arts. 1902-1903 CC), criminal liability (Arts. 199-200 CP, 1-4 years imprisonment).