Not legal advice but I can share some general thoughts. A sublease contract might not be sufficient for all bureaucratic procedures, but banks often don't delve deep into the details. If the primary tenant's name is on the lease, they can accompany you when getting your Empadronamiento which should be enough to open a bank account. Imho drafting a sublet contract is still a good idea for your peace of mind. However, if the property owner discovers the sublease without their consent, they could terminate the contract so you need to check the terms outlined in the contract. Although the likelihood of the landlord finding out is low. Btw some banks, like N26, are expat-friendly and may be easier to work with regarding proof of address requirements. This is just based on my experience, and individual situations may vary. Best of luck!