The preliminary ratings assigned by S&P Global Ratings to the prime floating-rate residential mortgage-backed securities (RMBS) to be issued by Perpetual Corporate Trust Ltd. as trustee for Barton Series 2023-1 Trust reflect the following factors. The credit risk of the underlying collateral portfolio (discussed in more detail under "Credit Assessment") and the credit support provided to each class of rated notes are commensurate with the ratings assigned. Subordination and lenders' mortgage insurance (LMI) cover provide credit support for the rated notes. The credit support provided to the rated notes is sufficient to cover the assumed losses at the applicable rating stress. Our assessment of credit risk takes into account the underwriting standards and approval process of Beyond Bank Australia Ltd.