Castell 2025-1 PLC is an RMBS transaction securitizing a portfolio of owner-occupied second-lien mortgage loans secured against properties in the U.K. Of the loans in the pool, 99.9% were originated in the past two years by UK Mortgage Lending Ltd., which is wholly owned by Pepper Money (PMB) Ltd. Prefunding of loans of up to 15% of the collateralized notes balance will take place up to the second interest payment date (IPD) using prefunding reserves plus up to £5 million of principal collections received on the first IPD. If these loans are not purchased, any unused prefunding amount will pay down the collateralized notes pro rata, while the unused principal collections will pay the class A notes. UK Mortgage Lending