Press Release

DBRS Morningstar Upgrades and Confirms Ratings on Castell 2018-1 PLC

RMBS
October 22, 2021

DBRS Ratings Limited (DBRS Morningstar) took the following rating actions on the notes issued by Castell 2018-1 PLC (the Issuer):

-- Class A confirmed at AAA (sf)
-- Class B confirmed at AAA (sf)
-- Class C upgraded to AAA (sf) from AA (sf)
-- Class D upgraded to AA (low) (sf) from A (sf)
-- Class E upgraded to A (low) (sf) from BBB (sf)
-- Class F upgraded to BBB (low) (sf) from BB (sf)

The ratings on the Class A, Class B, Class C, Class D, Class E, and Class F notes address the timely payment of interest and ultimate payment of principal on or before the legal final maturity date in January 2046.

The rating actions follow an annual review of the transaction and are based on the following analytical considerations:
-- Portfolio performance, in terms of delinquencies, defaults, and losses.
-- Portfolio default rate (PD), loss given default (LGD), and expected loss assumptions on the remaining receivables.
-- Current available credit enhancement to the notes to cover the expected losses at their respective rating levels.
-- Current economic environment and an assessment of sustainable performance, as a result of the Coronavirus Disease (COVID-19) pandemic.

The Issuer is a bankruptcy-remote special-purpose vehicle incorporated in the United Kingdom. The issuer used the notes to fund the purchase of UK second-lien mortgage loans originated by Optimum Credit Limited, a specialist mortgage provider based in Cardiff, Wales.

PORTFOLIO PERFORMANCE
As of July 2021, loans that were two- to three-months in arrears represented 0.5% of the outstanding balance, the 90+ delinquency ratio was 3.5%, and the cumulative loss ratio was zero.

PORTFOLIO ASSUMPTIONS AND KEY DRIVERS
DBRS Morningstar conducted a loan-by-loan analysis of the remaining pool of receivables and has updated its base case PD and LGD assumptions to 10.1% and 37.6%, respectively.

CREDIT ENHANCEMENT
As of the July 2021 payment date, credit enhancement to the Class A, Class B, Class C, Class D, Class E, and Class F notes was 65.8%, 51.3%, 37.9%, 28.7%, 21.9%, and 14.4%, up from 48.7%, 34.9%, 25.1%, 18.4%, 13.5%, and 8.0% in July 2020, respectively.

The transaction benefits from a general reserve fund of GBP 6.9 million and a liquidity reserve fund of GBP 1.5 million. The general reserve fund covers senior fees as well as interest and principal (via the principal deficiency ledgers) on the rated notes. The liquidity reserve fund covers senior fees and interest on the Class A notes and Class B notes.

Citibank N.A., London Branch acts as the account bank for the transaction. Based on the DBRS Morningstar private rating of Citibank N.A., London Branch, 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 rating assigned to the Class A notes, as described in DBRS Morningstar's "Legal Criteria for European Structured Finance Transactions" methodology.

NatWest Markets Plc acts as the swap counterparty for the transaction. DBRS Morningstar's public Long-Term Critical Obligations Rating of NatWest Markets Plc at A (high) is above the First Rating Threshold as described in DBRS Morningstar's "Derivative Criteria for European Structured Finance Transactions" methodology.

DBRS Morningstar analysed the transaction structure in Intex DealMaker.

The Coronavirus Disease (COVID-19) and the resulting isolation measures have caused an immediate economic contraction, leading in some cases to increases in unemployment rates and income reductions for many borrowers. DBRS Morningstar anticipates that delinquencies may continue to increase in the coming months for many structured finance transactions. The ratings are based on additional analysis to expected performance as a result of the global efforts to contain the spread of the coronavirus. For this transaction, DBRS Morningstar incorporated an increase in PD for certain borrower characteristics and assessed a potential reduction in portfolio prepayment rates.

The DBRS Morningstar Sovereign group releases baseline macroeconomic scenarios for rated sovereigns. These scenarios were last updated on 8 September 2021. DBRS Morningstar analysis considered impacts consistent with the baseline scenario in the below referenced report. For details, see the following commentaries: https://www.dbrsmorningstar.com/research/384150/baseline-macroeconomic-scenarios-for-rated-sovereigns and https://www.dbrsmorningstar.com/research/384482/baseline-macroeconomic-scenarios-application-to-credit-ratings.

On 14 June 2021, DBRS Morningstar updated its 5 May 2020 commentary outlining the impact of the coronavirus crisis on performance of DBRS Morningstar-rated RMBS transactions in Europe one year on. For more details, please see: https://www.dbrsmorningstar.com/research/380094/the-impact-of-covid-19-on-european-mortgage-performance-one-year-on and https://www.dbrsmorningstar.com/research/360599/european-rmbs-transactions-risk-exposure-to-coronavirus-covid-19-effect.

ESG CONSIDERATIONS
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/373262.

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

The principal methodology applicable to the ratings is the “Master European Structured Finance Surveillance Methodology” (8 February 2021).

Other methodologies referenced in this transaction are listed at the end of this press release. These may be found at: http://www.dbrsmorningstar.com/about/methodologies.

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 rating action.

For a more detailed discussion of the sovereign risk impact on Structured Finance 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/381451/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 ratings include investor reports provided by Citibank N.A., London Branch, and loan-level data provided by Optimum Credit Limited.

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

At the time of the initial rating, 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 ratings to be of satisfactory quality.

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

The last rating action on this transaction took place on 23 October 2020, when DBRS Morningstar confirmed the rating on the Class A notes and upgraded the ratings on the Class B, Class C, Class D, Class E, and Class F notes to AAA (sf), AA (sf), A (sf), BBB (sf), and BB (sf), respectively.

The lead analyst responsibilities for this transaction have been transferred to Natalia Coman.

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

To assess the impact of changing the transaction parameters on the rating, DBRS Morningstar considered the following stress scenarios as compared with the parameters used to determine the 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 are 10.1% and 37.6%, respectively.
-- The risk sensitivity overview below illustrates the ratings expected if the PD and LGD increase by a certain percentage over the base case assumption. For example, if the LGD increases by 50%, the rating on the Class A notes would be expected to remain at AAA (sf), assuming no change in the PD. If the PD increases by 50%, the rating on the Class A notes would be expected to remain at AAA (sf), assuming no change in the LGD. Furthermore, if both the PD and LGD increase by 50%, the rating on the Class A notes would be expected to remain at AAA (sf).

Class A Risk Sensitivity:
-- 25% increase in LGD, expected rating of AAA (sf)
-- 50% increase in LGD, expected rating of AAA (sf)
-- 25% increase in PD, expected rating of AAA (sf)
-- 50% increase in PD, expected rating of AAA (sf)
-- 25% increase in PD and 25% increase in LGD, expected rating of AAA (sf)
-- 25% increase in PD and 50% increase in LGD, expected rating of AAA (sf)
-- 50% increase in PD and 25% increase in LGD, expected rating of AAA (sf)
-- 50% increase in PD and 50% increase in LGD, expected rating of AAA (sf)

Class B Risk Sensitivity:
-- 25% increase in LGD, expected rating of AAA (sf)
-- 50% increase in LGD, expected rating of AAA (sf)
-- 25% increase in PD, expected rating of AAA (sf)
-- 50% increase in PD, expected rating of AAA (sf)
-- 25% increase in PD and 25% increase in LGD, expected rating of AAA (sf)
-- 25% increase in PD and 50% increase in LGD, expected rating of AAA (sf)
-- 50% increase in PD and 25% increase in LGD, expected rating of AA (high) (sf)
-- 50% increase in PD and 50% increase in LGD, expected rating of AA (high) (sf)

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

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

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

Class F Risk Sensitivity:
-- 25% increase in LGD, expected rating of BB (high) (sf)
-- 50% increase in LGD, expected rating of BB (high) (sf)
-- 25% increase in PD, expected rating of BB (high) (sf)
-- 50% increase in PD, expected rating of BB (high) (sf)
-- 25% increase in PD and 25% increase in LGD, expected rating of BB (sf)
-- 25% increase in PD and 50% increase in LGD, expected rating of BB (low) (sf)
-- 50% increase in PD and 25% increase in LGD, expected rating of BB (low) (sf)
-- 50% increase in PD and 50% increase in LGD, expected 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: http://cerep.esma.europa.eu/cerep-web/statistics/defaults.xhtml. DBRS Morningstar understands further information on DBRS Morningstar historical default rates may be published by the Financial Conduct Authority (FCA) on its webpage: https://www.fca.org.uk/firms/credit-rating-agencies.

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

Lead Analyst: Natalia Coman, Assistant Vice President
Rating Committee Chair: Alfonso Candelas, Senior Vice President
Initial Rating Date: 8 October 2018

DBRS Ratings Limited
20 Fenchurch Street, 31st Floor,
London EC3M 3BY United Kingdom
Tel. +44 (0) 20 7855 6600
Registered and incorporated under the laws of England and Wales: Company No. 7139960

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

-- Legal Criteria for European Structured Finance Transactions (29 July 2021), https://www.dbrsmorningstar.com/research/382171/legal-criteria-for-european-structured-finance-transactions.
-- Master European Structured Finance Surveillance Methodology (8 February 2021), https://www.dbrsmorningstar.com/research/373435/master-european-structured-finance-surveillance-methodology.
-- Operational Risk Assessment for European Structured Finance Servicers (16 September 2021), https://www.dbrsmorningstar.com/research/384513/operational-risk-assessment-for-european-structured-finance-servicers.
-- European RMBS Insight Methodology (3 June 2021) and European RMBS Insight Model v5.2.0.0, https://www.dbrsmorningstar.com/research/379557/european-rmbs-insight-methodology.
-- European RMBS Insight: UK Addendum (9 October 2020), https://www.dbrsmorningstar.com/research/368132/european-rmbs-insight-uk-addendum.
-- Interest Rate Stresses for European Structured Finance Transactions (24 September 2021), https://www.dbrsmorningstar.com/research/384920/interest-rate-stresses-for-european-structured-finance-transactions.
-- DBRS Morningstar Criteria: Approach to Environmental, Social, and Governance Risk Factors in Credit Ratings (3 February 2021), https://www.dbrsmorningstar.com/research/373262/dbrs-morningstar-criteria-approach-to-environmental-social-and-governance-risk-factors-in-credit-ratings.
-- Derivative Criteria for European Structured Finance Transactions (20 September 2021), https://www.dbrsmorningstar.com/research/384624/derivative-criteria-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 http://www.dbrsmorningstar.com/research/278375.

For more information on this credit or on this industry, visit www.dbrsmorningstar.com or contact us at [email protected].

ALL MORNINGSTAR DBRS RATINGS ARE SUBJECT TO DISCLAIMERS AND CERTAIN LIMITATIONS. PLEASE READ THESE DISCLAIMERS AND LIMITATIONS AND ADDITIONAL INFORMATION REGARDING MORNINGSTAR DBRS RATINGS, INCLUDING DEFINITIONS, POLICIES, RATING SCALES AND METHODOLOGIES.