Grosvenor Square RMBS 2023-1 PLC (GSQ 2023-1) is a static RMBS transaction that securitizes a portfolio of owner occupied and buy-to-let (BTL) mortgage loans secured on properties in the U.K. The transaction also has a prefunding mechanism under which the issuer can only purchase loans currently securitized within Finsbury Square 2020-2 PLC, a transaction we currently rate. Most loans in the pool (99.9%) were originated by Kensington Mortgages Company Ltd. (KMC), a non-bank specialist lender. The remaining 0.1% of the pool were originated by Southern Pacific Mortgages Ltd., Southern Pacific Personal Loans Ltd., and Money Partners Ltd. For this sub-pool, KMC previously acquired the loans from the respective originators and is currently the legal titleholder to each of the loans.