Can a tenant break a lease early without penalty under any circumstances?

This depends primarily on the specific terms of your lease or rent agreement — most agreements specify what happens if a tenant wants to leave before the term ends, often requiring a notice period and, in some cases, forfeiture of part or all of the security deposit as a form of penalty for early termination.

Some agreements include a "lock-in period" during which early termination isn't permitted at all (or comes with a specific, sometimes significant, penalty), while others are more flexible and simply require reasonable advance notice without any additional financial penalty.

If your circumstance is genuinely unavoidable (such as a job relocation or medical emergency), it's often worth discussing this directly and honestly with your landlord, since many landlords are willing to negotiate reasonable terms for an early exit rather than insisting on the strict letter of the agreement, particularly if you help find a suitable replacement tenant. Review your specific agreement's early termination clause carefully, and consult a lawyer if you're facing an unreasonable penalty demand from your landlord.