A theft loss waiver (TLW) is an agreement by which a second or third party agrees to cover the costs of losses to a rented vehicle resulting from theft in place of the renter. This agreement is typically offered by car rental companies in exchange for a fee.
A TLW is not an insurance policy, but simply an agreement by another party (typically the owner of the rental vehicle) to waive their right to claim reimbursement from the renter for losing their vehicle while it was in their possession.
If a rented vehicle is covered by a comprehensive car insurance policy, a TLW will normally cover the comprehensive car insurance deductible which the renter would otherwise be liable to pay out of their own pocket.
Theft loss waivers are typically included in loss damage waivers (LDWs) and collision damage waivers (CDWs), but this is not always the case. A TDW agreement may also place limitations on applicability, such as requirements to observe due diligence requirements in order to benefit from the agreement. For this reason, it is important to review the terms and conditions of a TDW, CDW or LDW before driving a rental vehicle.
The complimentary CDW benefits which come with some Swiss credit cards include a TDW in that they waive liability for theft or rental cars (this is covered by the card issuer or a third-party insurance provider), up to a certain limit. Some Swiss credit cards provide actual comprehensive car insurance for rental vehicles which also covers theft, rather than a simple waiver of responsibility. Reviewing the benefits provided by your credit card can help you determine whether you need an additional CDW or TDW.
More on this topic:
Swiss credit card rental car benefits explained