Castell 2022-1 PLC is an RMBS transaction originated by UK Mortgage Lending Ltd. (formerly known as Optimum Credit Ltd.) that securitizes a portfolio of £301 million second-ranking mortgage loans secured over properties in the U.K. This is the fourth RMBS transaction originated by UK Mortgage Lending that we have rated. The first was Castell 2019-1 PLC. The assets backing the notes are U.K. second-ranking mortgage loans. Most of the pool is considered prime, with 86.4% originated under UK Mortgage Lending's prime product range. Additionally, 3.5% of the pool refers to loans advanced to borrowers under UK Mortgage Lending's "near prime" product, with the remaining 10.1% loans advanced to borrowers under its "Optimum+" product. Loans advanced under the "near prime" or