Tower Bridge Funding 2023-1 PLC (TBF 2023-1) is an RMBS transaction that securitizes a portfolio of buy-to-let (BTL) and owner-occupied mortgage loans secured on properties in the U.K. The loans in the pool were originated between 2017 and 2022 by Belmont Green Finance Ltd. (BGFL), a nonbank specialist lender, via its specialist mortgage lending brand, Vida Homeloans. Around 67% of the transaction was previously securitized in the Tower Bridge Funding No. 4 transaction, for which we reviewed the performance history. The collateral comprises complex income borrowers with limited credit impairments, and there is a high exposure to self-employed, contractors, and first-time buyers. Approximately 78.5% of the pool comprises BTL loans and the remaining 21.5% are owner-occupier loans. Product switches and