It is, together with the practice Uría & Menéndez, one of only two Spanish firms mentioned, alongside international firms such as White & Case, Norton Rose, Holland & Knight, Gates & Partners, Fulbright & Jaworski and Clifford Chance, amongst others. Airfinance Journal publishes this guide every year, having previously carried out a survey of more than 120 senior management figures from the most important companies in the aeronautical sector worldwide to find out their opinion on the legal advice they receive and their preferred firms when they contract this type of service.

With regard to JAUSAS, the magazine notes that "this Spanish firm advises on issues including EU and Spanish regulations, contracts relating to the use and operation of aircraft, regulatory and contractual issues related to air travel. It also regularly advises clients on day-to-day matters such as securing and maintaining governmental and regulatory licenses and permits, landing rights and spot allocation, aircraft purchase and sale agreements, lease agreements and engine maintenance agreements, and engine lease agreements".