DBRS Morningstar Confirms Credit Ratings on Durham Mortgages B plc

DBRS Ratings Limited (DBRS Morningstar) confirmed its credit ratings on the following notes (together, the Rated Notes) issued by Durham Mortgages B plc (the Issuer):

-- Class A Notes at AAA (sf)
-- Class B Notes at AA (sf)
-- Class C Notes at A (sf)
-- Class D Notes at BBB (sf)
-- Class E Notes at BB (sf)
-- Class F Notes at B (sf)
-- Class X Notes at BB (sf)

The credit rating on the Class A Notes addresses the timely payment of interest and the ultimate repayment of principal by the legal final maturity date. The credit rating on the Class B Notes addresses the ultimate payment of interest and principal on or before the legal final maturity date while junior and the timely payment of interest while the most senior class outstanding. The credit ratings on the Class C, Class D, Class E, Class F, and Class X Notes address the ultimate payment of interest and the ultimate repayment of principal by the legal final maturity date.

The confirmations follow an annual review of the transaction and are based on the following analytical considerations:
-- Portfolio performance, in terms of delinquencies, defaults, and losses, as of the November 2023 payment date;
-- Portfolio default rate (PD), loss given default (LGD), and expected loss assumptions on the remaining receivables; and
-- Current available credit enhancement to the notes to cover the expected losses at their respective credit rating levels.

The transaction is a securitisation of buy-to-let residential mortgages originated by Bradford & Bingley plc, Mortgage Express, GMAC, Kensington Mortgages Limited, and Close Brothers Group plc; sold by Cornwall Home Loans Limited; and serviced by Topaz Finance Limited.

PORTFOLIO PERFORMANCE
As of 31 October 2023, loans two to three months in arrears represented 1.9% of the outstanding portfolio balance, up from 0.7% one year prior. Loans more than three months in arrears represented 7.6%, up from 2.2% one year prior. The cumulative default ratio was 0.6%.

PORTFOLIO ASSUMPTIONS AND KEY DRIVERS
DBRS Morningstar conducted a loan-by-loan analysis of the remaining pool of receivables and updated its base case PD and LGD assumptions at the B (sf) credit rating level to 10.9% and 18.2%, respectively.

CREDIT ENHANCEMENT
Credit enhancement to the Rated Notes is provided by the subordination of the junior notes and a general reserve fund. As of the November 2023 payment date, credit enhancement to the Rated Notes had increased from the time of DBRS Morningstar’s initial credit rating as follows:
-- Class A Notes: 23.5%, up from 15.8%;
-- Class B Notes: 17.7%, up from 11.8%;
-- Class C Notes: 12.8%, up from 8.4%;
-- Class D Notes: 8.5%, up from 5.4%;
-- Class E Notes: 5.3%, up from 3.2%; and
-- Class F Notes: 3.3%, up from 1.9%.

The transaction benefits from a liquidity reserve fund, which covers senior fees and interest on the Class A Notes. The liquidity reserve fund is funded to its target level of GBP 7.5 million, equal to 0.5% of the Class A Notes’ initial balance.

The general reserve fund is nonamortising and covers senior fees, interest on the Class A to Class F Notes (where the Class B to Class F Notes are subject to a principal deficiency ledger (PDL) condition of 10%), and principal losses via the PDLs on the Class A to Class F Notes. The general reserve fund is funded to its target balance of GBP 21.9 million, equal to 1.25% of the initial portfolio balance.

Citibank N.A./London Branch (Citibank London) acts as the account bank for the transaction. Based on DBRS Morningstar’s private credit rating on Citibank London, the downgrade provisions outlined in the transaction documents, and other mitigating factors inherent in the transaction structure, DBRS Morningstar considers the risk arising from the exposure to the account bank to be consistent with the credit rating assigned to the Class A Notes, as described in DBRS Morningstar's "Legal Criteria for European Structured Finance Transactions" methodology.

DBRS Morningstar’s credit ratings on the notes address the credit risk associated with the identified financial obligations in accordance with the relevant transaction documents.

DBRS Morningstar’s credit ratings on the notes also address the credit risk associated with the increased rate of interest applicable to the notes if the notes are not redeemed on the Optional Redemption Date (as defined in and) in accordance with the applicable transaction documents.

DBRS Morningstar’s credit ratings do not address non-payment risk associated with contractual payment obligations contemplated in the applicable transaction documents that are not financial obligations.

DBRS Morningstar’s long-term credit ratings provide opinions on risk of default. DBRS Morningstar considers risk of default to be the risk that an issuer will fail to satisfy the financial obligations in accordance with the terms under which a long-term obligation has been issued.

ENVIRONMENTAL, SOCIAL, GOVERNANCE CONSIDERATIONS
There were no Environmental/Social/Governance factors that had a significant or relevant effect on the credit analysis.

A description of how DBRS Morningstar considers ESG factors within the DBRS Morningstar analytical framework can be found in the DBRS Morningstar Criteria: Approach to Environmental, Social, and Governance Risk Factors in Credit Ratings at https://www.dbrsmorningstar.com/research/416784/dbrs-morningstar-criteria-approach-to-environmental-social-and-governance-risk-factors-in-credit-ratings.

DBRS Morningstar analysed the transaction structure in Intex DealMaker.

Notes:
All figures are in British pound sterling unless otherwise noted.

The principal methodology applicable to the credit ratings is the “Master European Structured Finance Surveillance Methodology” (11 December 2023), https://www.dbrsmorningstar.com/research/425148/master-european-structured-finance-surveillance-methodology.

Other methodologies referenced in this transaction are listed at the end of this press release.

DBRS Morningstar has applied the principal methodology consistently and conducted a review of the transaction in accordance with the principal methodology.

A review of the transaction legal documents was not conducted as the legal documents have remained unchanged since the most recent credit rating action.

For a more detailed discussion of the sovereign risk impact on Structured Finance credit ratings, please refer to “Appendix C: The Impact of Sovereign Ratings on Other DBRS Morningstar Credit Ratings” of the “Global Methodology for Rating Sovereign Governments” at: https://www.dbrsmorningstar.com/research/421590/global-methodology-for-rating-sovereign-governments.

The DBRS Morningstar Sovereign group releases baseline macroeconomic scenarios for rated sovereigns. DBRS Morningstar analysis considered impacts consistent with the baseline scenarios as set forth in the following report: https://www.dbrsmorningstar.com/research/384482/baseline-macroeconomic-scenarios-application-to-credit-ratings.

The sources of data and information used for these credit ratings include investor reports provided by Citibank London and loan-level data provided by EuroABS Ltd.

DBRS Morningstar did not rely upon third-party due diligence in order to conduct its analysis.

At the time of the initial credit ratings, DBRS Morningstar was supplied with third-party assessments. However, this did not impact the rating analysis.

DBRS Morningstar considers the data and information available to it for the purposes of providing these credit ratings to be of satisfactory quality.

DBRS Morningstar does not audit or independently verify the data or information it receives in connection with the credit rating process.

The last credit rating action on this transaction took place on 19 December 2022, when DBRS Morningstar confirmed its credit ratings on the Class A, Class D, Class E, Class F, and Class X Notes at AAA (sf), BBB (sf), BB (sf), B (sf), and BB (sf), respectively, and upgraded its credit ratings on the Class B and Class C Notes to AA (sf) and A (sf) from AA (low) (sf) and A (low) (sf), respectively. At the same time, DBRS Morningstar removed all credit ratings in the transaction from Under Review with Positive Implications following the finalisation of DBRS Morningstar’s “European RMBS Insight: UK Addendum” methodology.

Information regarding DBRS Morningstar credit ratings, including definitions, policies, and methodologies, is available at www.dbrsmorningstar.com.

Sensitivity Analysis: To assess the impact of changing the transaction parameters on the credit ratings, DBRS Morningstar considered the following stress scenarios as compared with the parameters used to determine the credit rating (the base case):

-- DBRS Morningstar expected a lifetime base case PD and LGD for the pool based on a review of the current assets. Adverse changes to asset performance may cause stresses to base case assumptions and therefore have a negative effect on credit ratings.
-- The base case PD and LGD of the current pool of loans for the Issuer at the B (sf) credit rating level are 10.9% and 18.2%, respectively.
-- The risk sensitivity overview below illustrates the credit ratings expected if the PD and LGD increase by a certain percentage over the base case assumption.

Class A Notes Risk Sensitivity:
-- 25% increase in LGD, expected credit rating of AA (high) (sf)
-- 50% increase in LGD, expected credit rating of AA (sf)
-- 25% increase in PD, expected credit rating of AA (high) (sf)
-- 50% increase in PD, expected credit rating of AA (low) (sf)
-- 25% increase in PD and 25% increase in LGD, expected credit rating of AA (low) (sf)
-- 25% increase in PD and 50% increase in LGD, expected credit rating of A (high) (sf)
-- 50% increase in PD and 25% increase in LGD, expected credit rating of A (high) (sf)
-- 50% increase in PD and 50% increase in LGD, expected credit rating of A (low) (sf)

Class B Notes Risk Sensitivity:
-- 25% increase in LGD, expected credit rating of A (high) (sf)
-- 50% increase in LGD, expected credit rating of A (high) (sf)
-- 25% increase in PD, expected credit rating of A (high) (sf)
-- 50% increase in PD, expected credit rating of A (low) (sf)
-- 25% increase in PD and 25% increase in LGD, expected credit rating of A (low) (sf)
-- 25% increase in PD and 50% increase in LGD, expected credit rating of BBB (high) (sf)
-- 50% increase in PD and 25% increase in LGD, expected credit rating of BBB (high) (sf)
-- 50% increase in PD and 50% increase in LGD, expected credit rating of BBB (sf)

Class C Notes Risk Sensitivity:
-- 25% increase in LGD, expected credit rating of A (low) (sf)
-- 50% increase in LGD, expected credit rating of BBB (high) (sf)
-- 25% increase in PD, expected credit rating of BBB (high) (sf)
-- 50% increase in PD, expected credit rating of BBB (sf)
-- 25% increase in PD and 25% increase in LGD, expected credit rating of BBB (sf)
-- 25% increase in PD and 50% increase in LGD, expected credit rating of BBB (low) (sf)
-- 50% increase in PD and 25% increase in LGD, expected credit rating of BB (high) (sf)
-- 50% increase in PD and 50% increase in LGD, expected credit rating of BB (high) (sf)

Class D Notes Risk Sensitivity:
-- 25% increase in LGD, expected credit rating of BB (high) (sf)
-- 50% increase in LGD, expected credit rating of BB (high) (sf)
-- 25% increase in PD, expected credit rating of BB (high) (sf)
-- 50% increase in PD, expected credit rating of BB (high) (sf)
-- 25% increase in PD and 25% increase in LGD, expected credit rating of BB (high) (sf)
-- 25% increase in PD and 50% increase in LGD, expected credit rating of BB (sf)
-- 50% increase in PD and 25% increase in LGD, expected credit rating of BB (low) (sf)
-- 50% increase in PD and 50% increase in LGD, expected credit rating of BB (low) (sf)

Class E Notes Risk Sensitivity:
-- 25% increase in LGD, expected credit rating of BB (low) (sf)
-- 50% increase in LGD, expected credit rating of B (high) (sf)
-- 25% increase in PD, expected credit rating of B (high) (sf)
-- 50% increase in PD, expected credit rating of B (sf)
-- 25% increase in PD and 25% increase in LGD, expected credit rating of B (high) (sf)
-- 25% increase in PD and 50% increase in LGD, expected credit rating of B (sf)
-- 50% increase in PD and 25% increase in LGD, expected credit rating below B (sf)
-- 50% increase in PD and 50% increase in LGD, expected credit rating below B (sf)

Class F Notes Risk Sensitivity:
-- 25% increase in LGD, expected credit rating below B (sf)
-- 50% increase in LGD, expected credit rating below B (sf)
-- 25% increase in PD, expected credit rating below B (sf)
-- 50% increase in PD, expected credit rating below B (sf)
-- 25% increase in PD and 25% increase in LGD, expected credit rating below B (sf)
-- 25% increase in PD and 50% increase in LGD, expected credit rating below B (sf)
-- 50% increase in PD and 25% increase in LGD, expected credit rating below B (sf)
-- 50% increase in PD and 50% increase in LGD, expected credit rating below B (sf)

Class X Notes Risk Sensitivity:
-- 25% increase in LGD, expected credit rating of BB (sf)
-- 50% increase in LGD, expected credit rating of BB (sf)
-- 25% increase in PD, expected credit rating of B (high) (sf)
-- 50% increase in PD, expected credit rating of B (high) (sf)
-- 25% increase in PD and 25% increase in LGD, expected credit rating of B (high) (sf)
-- 25% increase in PD and 50% increase in LGD, expected credit rating of B (high) (sf)
-- 50% increase in PD and 25% increase in LGD, expected credit rating of B (high) (sf)
-- 50% increase in PD and 50% increase in LGD, expected credit rating of B (high) (sf)

For further information on DBRS Morningstar historical default rates published by the European Securities and Markets Authority (ESMA) in a central repository, see: https://registers.esma.europa.eu/cerep-publication. For further information on DBRS Morningstar historical default rates published by the Financial Conduct Authority (FCA) in a central repository, see https://data.fca.org.uk/#/ceres/craStats.

These credit ratings are endorsed by DBRS Ratings GmbH for use in the European Union.

Lead Analyst: Clare Wootton, Vice President
Rating Committee Chair: Alfonso Candelas, Senior Vice President
Initial Rating Date: 16 August 2021

DBRS Ratings Limited
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London EC1Y 1HQ United Kingdom
Tel. +44 (0) 20 7855 6600
Registered and incorporated under the laws of England and Wales: Company No. 7139960

The credit rating methodologies used in the analysis of this transaction can be found at: https://www.dbrsmorningstar.com/about/methodologies.

-- Legal Criteria for European Structured Finance Transactions (30 June 2023), https://www.dbrsmorningstar.com/research/416730/legal-criteria-for-european-structured-finance-transactions.
-- Master European Structured Finance Surveillance Methodology (11 December 2023), https://www.dbrsmorningstar.com/research/425148/master-european-structured-finance-surveillance-methodology.
-- DBRS Morningstar Criteria: Approach to Environmental, Social, and Governance Risk Factors in Credit Ratings (4 July 2023), https://www.dbrsmorningstar.com/research/416784/dbrs-morningstar-criteria-approach-to-environmental-social-and-governance-risk-factors-in-credit-ratings.
-- Operational Risk Assessment for European Structured Finance Servicers (15 September 2023), https://www.dbrsmorningstar.com/research/420572/operational-risk-assessment-for-european-structured-finance-servicers.
-- European RMBS Insight Methodology (27 March 2023), https://www.dbrsmorningstar.com/research/411634/european-rmbs-insight-methodology.
-- European RMBS Insight: UK Addendum (11 August 2023) and European RMBS Insight Model v 6.0.1.0, https://www.dbrsmorningstar.com/research/419141/european-rmbs-insight-uk-addendum.
-- Interest Rate Stresses for European Structured Finance Transactions (15 September 2023),
https://www.dbrsmorningstar.com/research/420602/interest-rate-stresses-for-european-structured-finance-transactions.

A description of how DBRS Morningstar analyses structured finance transactions and how the methodologies are collectively applied can be found at https://www.dbrsmorningstar.com/research/278375.

For more information on this credit or on this industry, visit www.dbrsmorningstar.com or contact us at info@dbrsmorningstar.com.