NATIONWIDE BUILDING SOCIETY

Regulatory Filings • Apr 18, 2019

IMPORTANT NOTICE

NOT FOR DISTRIBUTION TO ANY U.S. PERSON OR TO ANY PERSON OR ADDRESS IN THE U.S. EXCEPT TO QUALIFIED INSTITUTIONAL BUYERS WHO ARE ALSO QUALIFIED PURCHASERS (EACH AS DEFINED BELOW)

IMPORTANT: You must read the following before continuing. The following applies to the supplement attached to this electronic transmission, and you are therefore advised to read this carefully before reading, accessing or making any other use of the supplement. In accessing the supplement, you agree to be bound by the following terms and conditions, including any modifications to them any time you receive any information from us as a result of such access.

NOTHING IN THIS ELECTRONIC TRANSMISSION CONSTITUTES AN OFFER TO SELL OR THE SOLICITATION OF AN OFFER TO BUY SECURITIES IN THE UNITED STATES OR ANY OTHER JURISDICTION WHERE IT IS UNLAWFUL TO DO SO. THE SECURITIES HAVE NOT BEEN, AND WILL NOT BE, REGISTERED UNDER THE UNITED STATES SECURITIES ACT OF 1933, AS AMENDED (THE SECURITIES ACT), OR THE SECURITIES LAWS OR "BLUE SKY" LAWS OF ANY STATE OR OTHER JURISDICTION OF THE UNITED STATES AND THEREFORE MAY NOT BE OFFERED, SOLD, RESOLD OR DELIVERED WITHIN THE UNITED STATES OR TO, OR FOR THE ACCOUNT OR BENEFIT OF, U.S. PERSONS (AS DEFINED IN REGULATION S (REGULATION S) UNDER THE SECURITIES ACT), EXCEPT PURSUANT TO AN EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND ANY APPLICABLE STATE OR LOCAL SECURITIES LAWS. ACCORDINGLY, THE NOTES ARE BEING OFFERED AND SOLD (I) TO PERSONS THAT ARE "QUALIFIED INSTITUTIONAL BUYERS" (QIBS) AS DEFINED IN RULE 144A UNDER THE SECURITIES ACT (RULE 144A) AND WHO ARE ALSO QUALIFIED PURCHASERS (QPS) WITHIN THE MEANING OF SECTION 2(A)(51)(A) OF THE UNITED STATES INVESTMENT COMPANY ACT OF 1940, AS AMENDED (THE INVESTMENT COMPANY ACT), IN EACH CASE ACTING FOR THEIR OWN ACCOUNT OR FOR THE ACCOUNT OF ONE OR MORE QIBS EACH OF WHICH IS ALSO A QP IN RELIANCE ON RULE 144A, OR (II) OUTSIDE THE UNITED STATES TO PERSONS OTHER THAN U.S. PERSONS IN RELIANCE ON REGULATION S. IN ADDITION, THE ISSUER HAS NOT BEEN AND WILL NOT BE REGISTERED UNDER THE INVESTMENT COMPANY ACT. THE NOTES ARE NOT TRANSFERABLE EXCEPT UPON SATISFACTION OF CERTAIN CONDITIONS AS DESCRIBED UNDER "TRANSFER RESTRICTIONS" HEREIN.

THE FOLLOWING SUPPLEMENT MAY NOT BE FORWARDED OR DISTRIBUTED TO ANY OTHER PERSON AND MAY NOT BE REPRODUCED IN ANY MANNER WHATSOEVER. ANY FORWARDING, DISTRIBUTION OR REPRODUCTION OF THIS DOCUMENT IN WHOLE OR IN PART IS UNAUTHORISED. FAILURE TO COMPLY WITH THIS DIRECTIVE MAY RESULT IN A VIOLATION OF THE SECURITIES ACT OR THE APPLICABLE LAWS OF OTHER JURISDICTIONS.

You are reminded that the supplement has been delivered to you on the basis that you are a person into whose possession this supplement may be lawfully delivered in accordance with the laws of the jurisdiction in which you are located and you may not, nor are you authorised to, deliver the supplement to any other person.

The materials relating to the offering do not constitute, and may not be used in connection with, an offer or solicitation in any place where offers or solicitations are not permitted by law. If a jurisdiction requires that the offering be made by a licensed broker or dealer and the lead managers or any affiliate of the lead managers is a licensed broker or dealer in that jurisdiction, the offering shall be deemed to be made by the lead managers or such affiliate on behalf of the issuer in such jurisdiction.

By accessing the supplement, you shall be deemed to have confirmed and represented to us that (a) you have understood and agree to the terms set out herein, (b) you consent to delivery of the supplement by electronic transmission, (c) you are either (i) not a U.S. person (within the meaning of Regulation S under the Securities Act) or acting for the account or benefit of a U.S. person and the electronic mail address that you have given to us and to which this e-mail has been delivered is not located in the United States, its territories and possessions (including Puerto Rico, the U.S. Virgin Islands, Guam, American Samoa, Wake Island and the Northern Mariana Islands) or the District of Columbia or (ii) a qualified institutional buyer (QIB) within the meaning of Rule 144A under the Securities Act (Rule 144A) and a qualified purchaser (QP) within the meaning of Section 2(a)(51)(A) of the United States Investment Company Act of 1940, as amended (the Investment Company Act), and the rules and regulations thereunder, in each case acting for your own account or for the account of one or more QIBs each of which is also a QP in reliance on Rule 144A and (d) if you are a person in the United Kingdom, then you are a person who (i) is an investment professional within the meaning of Article 19 of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005 (the FPO) or (ii) is a high net worth entity falling within Article 49(2)(a) to (d) of the FPO (all such persons together being referred to as relevant persons). This supplement must not be acted on or relied on by persons who are not relevant persons. Any investment or investment activity to which this supplements relates is available only to relevant persons and will be engaged in only with relevant persons.

MIFID II product governance / target market – Solely for the purposes of each manufacturer's product approval process, the target market assessment in respect of the notes has led to the conclusion that: (i) the target market for the notes is eligible counterparties and professional clients only, each as defined in MiFID II; and (ii) all channels for distribution of the notes to eligible counterparties and professional clients are appropriate. Any person subsequently offering, selling or recommending the notes (a distributor) should take into consideration the manufacturers' target market assessment; however, a distributor subject to MiFID II is responsible for undertaking its own target market assessment in respect of the notes (by either adopting or refining the manufacturers' target market assessment) and determining appropriate distribution channels.

IMPORTANT – EEA RETAIL INVESTORS – The notes are not intended to, and should not, be offered, sold or otherwise made available to any retail investor in the European Economic Area (EEA). For these purposes, a retail investor means a person who is one (or more) of: (i) a retail client as defined in point (11) of Article 4(1) of MiFID II; or (ii) a customer within the meaning of Directive 2002/92/EC (as amended, IMD), where that customer would not qualify as a professional client as defined in point (10) of Article 4(1) of MiFID II. Consequently no key information document required by Regulation (EU) No 1286/2014 (as amended, the PRIIPs Regulation) for offering or selling the notes or otherwise making them available to retail investors in the EEA has been prepared and therefore offering or selling the notes or otherwise making them available to any retail investor in the EEA may be unlawful under the PRIIPs Regulation.

This supplement has been sent to you in an electronic form. You are reminded that documents transmitted via this medium may be altered or changed during the process of electronic transmission and consequently neither Silverstone Master Issuer PLC nor Nationwide Building Society nor any dealers or nor any person who controls, nor any director, officer, employee or agent of Silverstone Master Issuer PLC or Nationwide Building Society or any dealer nor any affiliate of any such person accepts any liability or responsibility whatsoever in respect of any difference between the supplement distributed to you in electronic format and the hard copy version available to you on request from Silverstone Master Issuer PLC or Nationwide Building Society.

SUPPLEMENT DATED 18 APRIL 2019 TO

THE BASE PROSPECTUS DATED 9 APRIL 2019 SILVERSTONE MASTER ISSUER PLC

(incorporated in England and Wales with limited liability with registered number 06612744)

Legal entity identifier (LEI): 549300P6OXWKM20QS303

£35,000,000,000

Residential Mortgage Backed Note Programme

(ultimately backed by the mortgages trust)

This supplement (the supplement) (including any documents incorporated by reference) is supplemental to the base prospectus (the base prospectus) dated 9 April 2019, which comprises a base prospectus for the purpose of Article 5.4 of Directive 2003/71/EC (the Prospectus Directive), constitutes a supplementary prospectus for the purposes of Section 87G of the Financial Services and Markets Act 2000 (the FSMA) and is prepared in connection with the above mentioned residential mortgage backed note programme (the Programme) established by Silverstone Master Issuer PLC (the issuer). Terms defined in the base prospectus have the same meaning when used in this Supplement.

This supplement is supplemental to, and should be read in conjunction with, the base prospectus and any other supplements to the base prospectus issued by the issuer. The issuer accepts responsibility for the information contained in this supplement. To the best of the knowledge of the issuer (who has taken all reasonable care to ensure that such is the case) the information contained in this supplement is in accordance with the facts and does not omit anything likely to affect the import of such information. To the extent that there is any inconsistency between (a) any statement in this supplement or any statement incorporated by reference into the base prospectus by this supplement and (b) any other statement in or incorporated by reference in the base prospectus, the statements in (a) above will prevail. Save as disclosed in this supplement, there has been no other significant new factor, material mistake or inaccuracy relating to information included in the base prospectus since the publication of the base prospectus.

Any notes issued pursuant to the Programme have not been and will not be registered under the United States Securities Act of 1933, as amended (the Securities Act), or the state securities laws of any state of the United States and may not be offered, sold or delivered in the United States or to, or for the account or benefit of, U.S. persons (as defined in Regulation S under the Securities Act (Regulation S)) except to persons that are qualified institutional buyers within the meaning of Rule 144A under the Securities Act who are also qualified purchasers within the meaning of the United States Investment Company Act of 1940, as amended, and the rules and regulations thereunder, or in transactions that occur outside the United States to persons other than U.S. persons in accordance with Regulation S or in other transactions exempt from registration under the Securities Act and, in each case, in compliance with applicable securities laws.

Purpose of this Supplement

The purpose of this Supplement is to set out changes resulting from updates in the S&P swap counterparty criteria in respect of certain Issuer Swaps.

The date of this supplement is 18 April 2019

The Amendments

The following amendments are being made to the Base Prospectus to reflect certain updates to the S&P swap counterparty criteria.

1. Amendments to "Triggers Tables—Rating Triggers Table" in the Base Prospectus

The section titled "The issuer swap provider" under "Triggers Tables—Rating Triggers Table" is updated in respect of the S&P requirements applicable to the issuer swaps as follows:

Required Ratings/Triggers Possible effects of Trigger being breached include the following

S&P Required Ratings

In respect of issuer swaps corresponding to notes issued prior to 1 April 2019 (the Pre-2019 issuer swaps), for so long as the notes corresponding to the relevant issuer swap are rated by S&P, the S&P required ratings and the corresponding possible effects of the relevant trigger being breached which are set out under "Funding 1 swap provider" apply with respect to the Pre-2019 issuer swaps as though:

• (i) each reference therein to "S&P relevant notes" were a reference to the notes corresponding to the relevant Pre-2019 issuer swap;
• (ii) each reference therein to "the Funding 1 swap provider" were a reference to "the issuer swap provider";
• (iii) each reference therein to "the Funding 1 fixed rate swap" were a reference to "the issuer swap"; and
• (iv) each reference therein to "Funding 1" were a reference to "the issuer".

In respect of issuer swaps corresponding to notes issued after 1 April 2019 (the 2019 onwards issuer swaps), for so long as the notes corresponding to the relevant issuer swap are rated by S&P, the S&P required ratings and the corresponding possible effects of the relevant trigger being breached are set out below, as though each reference therein to S&P relevant notes were a reference to the notes corresponding to the relevant 2019 onwards issuer swap.

The relevant S&P required ratings depend on which S&P framework is elected by the issuer swap provider from time to time (the S&P framework) and the rating of the notes corresponding to the relevant 2019 onwards issuer swap. There are four S&P frameworks; Strong, Adequate, Moderate and Weak.

Following the loss of any S&P required rating, during the relevant period, the issuer swap provider may, in addition to each of the remedies set out below, elect to change the S&P framework in order to cure the breach of the ratings trigger (i.e. where the issuer swap provider has the required ratings under another S&P framework but does not have the required ratings under the S&P framework currently in effect).

Current rating of the relevant notes	S&P framework Strong		S&P framework Adequate		S&P framework Moderate		S&P framework Weak
	S&P initial required rating	S&P subsequent required rating	S&P initial required rating	S&P subsequent required rating	S&P initial required rating	S&P subsequent required rating	S&P required rating
AAA	A-	BBB+	A-	A-	A	A	A+
AA+	A-	BBB+	A-	A-	A-	A-	A+
AA	A-	BBB	BBB+	BBB+	A-	A-	A
AA-	A-	BBB	BBB+	BBB+	BBB+	BBB+	A
A+	A-	BBB-	BBB	BBB	BBB+	BBB+	A
A	A-	BBB-	BBB	BBB	BBB	BBB	BBB+
A-	A-	BBB-	BBB	BBB-	BBB	BBB	BBB+
BBB+	A-	BBB-	BBB	BBB-	BBB	BBB-	BBB
BBB	A-	BBB-	BBB	BBB-	BBB	BBB-	BBB
BBB-	A-	BBB-	BBB	BBB-	BBB	BBB-	BBB
BB+ and below	A-	At least as high as 3 notches below the Relevant Notes rating	BBB	At least as high as 2 notches below the Relevant Notes rating	BBB	At least as high as 1 notch below the Relevant Notes rating	At least as high as the Relevant Notes rating

S&P required ratings: The S&P required ratings with respect to 2019 onwards issuer swaps are set out in the tables below.

The issuer swap provider or any relevant guarantor will have the relevant S&P required rating if its issuer credit rating or its resolution counterparty rating assigned by S&P is at least as high as the applicable S&P required rating corresponding to the then current rating of the relevant notes and the applicable S&P framework as specified in the above table.

In respect of a 2019 onwards issuer swap, the issuer swap provider and any applicable guarantor fails to have any S&P initial required rating where S&P framework Strong, Adequate or Moderate applies.

In respect of a 2019 onwards issuer swap, the issuer swap provider and any applicable guarantor fails to have any S&P subsequent required rating where S&P framework Strong, Adequate or Moderate applies.

The issuer swap provider must provide collateral within 10 business days (to the extent required depending on the value of the issuer swap) unless it (i) transfers its obligations to an entity that is eligible to be a swap provider under the S&P ratings criteria, (ii) obtains a guarantee from an entity with the S&P subsequent required ratings, or (iii) takes such other action as is required to maintain, or restore, the rating of the notes corresponding to the relevant issuer swap.

The issuer may terminate the relevant issuer swap if the issuer swap provider fails to provide collateral in respect of the issuer swap in the relevant time period (to the extent the issuer swap provider is required to do so).

The issuer swap provider must use its commercially reasonable efforts to, within 90 calendar days, either (i) transfer its rights and obligations to an entity that is eligible to be a swap provider under the S&P ratings criteria, (ii) obtain a guarantee from an entity with at least

the S&P subsequent required ratings, or (iii) take such other action as is required to maintain, or restore, the rating of the notes corresponding to the relevant issuer swap.

Whilst this process is on-going, the issuer swap provider must also provide collateral within 10 business days (to the extent required depending on the value of the issuer swap).

The issuer may terminate the relevant issuer swap if the issuer swap provider fails to provide collateral in respect of the issuer swap in the relevant time period (to the extent the issuer swap provider is required to do so). The issuer may also terminate the relevant issuer swap if the issuer swap provider either fails to use its commercially reasonable efforts to take the relevant actions or the relevant time period has expired.

In respect of a 2019 onwards swaps, the issuer swap provider and any applicable guarantor fails to have any S&P required rating where S&P framework Weak applies.

The issuer swap provider must use its commercially reasonable efforts to, within 90 calendar days, either (i) transfer its obligations to an entity that is eligible to be a swap provider under the S&P ratings criteria, (ii) obtain a guarantee from an entity with at least the S&P subsequent required ratings, or (iii) take such other action as is required to maintain, or restore, the rating of the notes corresponding to the relevant issuer swap.

There is no requirement to provide collateral whilst the process is on-going.

The issuer may terminate the relevant issuer swap if the issuer swap provider either fails to use its commercially reasonable efforts to take the relevant actions or the relevant time period has expired.