Exhibit 99.4

EXECUTIVE SUMMARY

SAN 2026-NQM5

By Clarifii LLC on June 8, 2026

CLARIFII CONTACT INFORMATION

OVERVIEW

Clarifii LLC (“Clarifii”) conducted an independent third-party pre-securitization due diligence review (the “Review”) of 110 Loans (the “Loans”) originated by a correspondent lender and acquired by Santander Bank N.A. (SBNA) (the “Client”) for the SAN 2026-NQM5 transaction. The Loans referenced in this narrative report were reviewed between 06/2025 to 05/2026 by Clarifii. This narrative report provides information about the scope of work performed by Clarifii, and the results of Clarifii’s review.

ORIGINATORS

Origination channels for the Loans in this review:

The Review consisted of a population of 110 Loans, with an aggregate principal balance of $51,877,021.00.

CLARIFII’S THIRD PARTY REVIEW (TPR) SCOPE OF WORK

The scope of work for this transaction consisted of credit, property valuation, and regulatory compliance reviews, plus a data integrity check, and were performed in accordance with rating agency loan level review standards in place as of the date of the review.

LOAN SAMPLING

The Clients defined the sample size and requested Clarifii to perform a random sample of the Loans to be included in the Review. To Clarifii’s knowledge, the Review covered 100% of the transaction Loan population.

The Review was conducted consistent with the criteria for the Nationally Recognized

Statistical Rating Organizations (“NRSROs”) specified below:

DATA INTEGRITY

Clarifii performed a data comparison review of the data fields provided by the Clients on the Loan tape to the data found in the Loan file as captured by Clarifii. This comparison, when specific data was available, included the following data fields and tolerance levels noted below.

CREDIT UNDERWRITING

Clarifii reviewed each Loan file to determine the adherence to defined underwriting or credit extension guidelines, standards, criteria, or other requirements provided by Clients, including, as applicable, Ability to Repay and Qualified Mortgage requirements. The Credit Qualification review consisted of the following:

To determine borrower program eligibility, Clarifii verified the following Loan attributes and, where applicable, recalculated based on the information provided:

Clarifii verified the following items per the Uniform Residential Loan Application Form 1003 (1003):

Clarifii verified the following items:

When applicable, Clarifii determined whether all supporting documentation as required by the guidelines and Ability to Repay/Qualified Mortgage Rule (ATR/QM) were complete and accurate. The documentation was used to verify whether the income used to qualify the Loan was calculated in accordance with the guidelines.  Documentation verified employment and income were deemed acceptable if it was a third-party document as required by the guidelines and ATR when applicable and may include:

For all Loans, Clarifii utilized the results from an independent, third-party fraud tool as well as information in the Loan file to identify and address any potential misrepresentations including:

Clarifii assessed whether the asset documentation required by the guidelines and ATR, when applicable, was present in the Loan file and within required timeframe.  Documentation used to verify assets for down payment, closing costs, prepaid items and reserves may have included:

Clarifii confirmed the presence of the insurance and tax information for the following:

DOCUMENT REVIEW

Clarifii reviewed each Loan file and verified if the following documents were included in the file and if the data on these documents was consistent (where applicable):

COMPLIANCE REVIEW

Clarifii reviewed each Loan file, when applicable, and verified that it was consummated in compliance with the applicable federal, state, and local anti-predatory lending statutes in effect at the time of origination of the mortgage loan. Compliance verification and validation that each mortgage Loan met the relevant provisions of:

Anti-Predatory Lending Requirements, that are imposed by federal, state and/or local statutory, regulatory, or authoritative determinations (e.g., state constitutional provisions, ordinances, interpretations, judicial determinations, etc.) that impose civil or criminal liability upon the Assignee or may cause significant loss severity to the value of the Loan, including the Home Ownership and Equity Protection Act (HOEPA) and any state and local high-cost home loan laws.  Assignee shall have the meaning as defined in the Truth in Lending Act (TILA).

Truth in Lending Act (TILA), as amended by HOEPA, 15 U.S.C. §1601 et seq., as implemented by Regulation Z, 12 C.F.R. Part 1026

Real Estate Settlement Procedures Act (RESPA), 12 U.S.C. §2603, as implemented by Regulation X, 12 C.F.R. Part 1024

Equal Credit Opportunity Act (ECOA), 15 U.S.C. §1691, as implemented by Regulation B, 12 C.F.R. §1001.1(b)

Clarifii reviewed the following documents as they related to regulatory compliance:

Loans were reviewed for violations of federal, state & local high cost, higher-priced and/or consumer finance laws and regulations that carry Assignee Liability, including those defined below. Any Loan that is determined to be classified and/or defined as high cost, higher-priced, subprime, threshold, predatory high risk, covered or similar classification/definition was reported.

Clarifii reverified and retested, when applicable, the following TILA and Regulation Z elements:

Reviewed and compared LEs and CDs with a report outlining any TILA violations, including a recalculation of disclosed finance charges, principal and interest calculations, proper completion of the Projected Payments table, total of payments, finance charges, amount financed, recalculation of disclosed APR and a review to determine if disclosure differences were within the allowed tolerances and disclosures were provided within the required timeframes. Testing was conducted to fulfill the elements Structured Finance Association (SFA) TRID Compliance Review Scope (“TRID Grid 3.0” v.12/05/2019).

Reviewed the TILA Right of Rescission, Notice of Right to Cancel, including a verification of the transaction date and expiration date, ensured proper execution of the Notice of Right to Cancel by all required parties, verified the disbursement date and determined if a full three (3) day rescission period was provided to the borrower(s). The appropriate Model Form was tested according to applicable U.S. Court of Appeals, Circuit Court rulings.

Reviewed to ensure the mortgage loan meets the applicable Qualified Mortgage (“QM”) and Ability-to-Repay (“ATR”) requirements as set forth in regulations promulgated by the Consumer Financial Protection Bureau as found at 12 CFR § 1026.43.

Reviewed to ensure compliance with RESPA/Regulation X documentation and timing requirements in effect at origination of the mortgage loan for RESPA disclosures (Servicing Disclosure Statement; Affiliated Business Arrangement Disclosure; Initial Escrow Disclosure Statement; List of Homeownership Counselling Organizations).

Confirmed compliance with the January 18, 2014, requirements regarding the disclosure of the right to receive a copy of appraisals within three (3) business days of application, the right to receive a copy of the appraisals at least three (3) business days prior to consummation and any applicable waiver. The disclosure of the right to receive a copy of appraisals was met by the disclosure on the Loan Estimate pursuant to 12 CFR § 1026.27(m)(1).

Confirmed compliance with the current FCRA/Regulation V requirements regarding risk-based pricing notice, credit score disclosure and Notice to Home Loan Applicant, as applicable.

The following is an itemization of the current and historical state and local anti-predatory lending requirements, considered customary in secondary market due diligence compliance testing and reviewed by Clarifii:

QUALIFIED MORTGAGE (QM)

With respect to QM (Safe Harbor and Rebuttable Presumption) designated Loans, Clarifii reviewed the Loan to determine whether, based on available information in the Loan file, (i) the Loan contained risky Loan features and terms (e.g. an interest only feature or negative amortization), (ii) the “points and fees” exceeded the applicable QM threshold, (iii) the monthly payment was calculated appropriately, (iv) the creditor considered and verified income or assets at or before consummation, (v) the creditor appropriately considered debt obligations, alimony and child support, and (vi) at the time of consummation, if the debt-to-income ratio exceeded 43% (calculated in accordance with Appendix Q to Regulation Z). This portion of the Review included a recalculation of all income and liabilities with attention to the appropriate documentation of each source.

If a Loan was designated as QM and identified as eligible for guarantee, purchase, or insurance by an applicable Agency, as permitted under the QM final rule, Clarifii reviewed the Loan to determine whether, based on available information in the Loan file the Loan satisfied (i), (ii) and (iii) in the preceding paragraph and reviewed the Automated Underwriting System output within the file to confirm agency eligibility.

For each QM designated Loan that satisfied the applicable requirements enumerated above, Clarifii then determined whether the Loan was a Safe Harbor QM or Rebuttable Presumption QM by comparing the Loan’s actual annual percentage rate, as recalculated, to the applicable average prime offer rate plus a certain applicable percentage.

ABILITY TO REPAY (ATR)

Clarifii reviewed the Loan to determine whether, based on available information in the Loan file, the creditor considered, as applicable, the following eight underwriting factors, and verified such information using reasonably reliable third-party records, at or before consummation: (i) the consumer’s current or reasonably expected income or assets, (ii) if the creditor relied on income from the consumer’s employment in determining repayment ability, the consumer’s current employment status; (iii) the consumer’s monthly payment; (iv) the consumer’s monthly payment on any simultaneous Loan that the creditor knows or has reason to know will be made; (v) the consumer’s monthly payment for mortgage-related obligations; (vi) the consumer’s current debt obligations, alimony, and child support; (vii) the consumer’s monthly debt-to-income ratio or residual income; and (viii) the consumer’s credit history. This portion of the Review also focused on full recalculation of income and debts, as well as the documentation provided to support each item used in originator’s determination of the ability to repay.

Note: for Loans designated as QM – Agency eligible (QM – Temporary), Clarifii did not review for compliance with the requirements of Appendix Q or General Ability to Repay.

Clarifii reviewed Loans to determine their conformity with the ATR/QM factors above, and did not render an independent assessment or opinion, warranty or represent that a Loan will be deemed to conform to Safe Harbor, Rebuttable Presumption, ATR, or other status based on any additional or revised factors that may be considered by legislative, regulatory, administrative, or judicial authorities (Authorities). Clarifii does not represent or warrant that the factors for which it has reviewed that the Loans constitute all the factors and/or criteria that Authorities may consider in determining the status of a Loan.

Clarifii’s review was based on information contained in the Loan file at the time it was provided for review.

VALUATION REVIEW

Clarifii reviewed all appraisals and alternative value tools used to qualify the Loan for reasonableness of estimated value, comparable sales, completeness of data and eligibility of the appraiser, compared to underwriting guidelines, variances, and tolerances.  Clarifii determined that the appraised value appeared to be supported, based on the valuation provided by the Independent Third-party Review.

INDEPENDENT THIRD-PARTY VALUES

Clarifii applied a cascade methodology to determine if the original appraisal value was reasonably supported when compared to an independent third-party valuation product.

Valuation Reconciliation Process:

Uniform Collateral Data Portal (UCDP) Risk Score:

VALUATION RESULTS SUMMARY

The table below summarizes the Loans that contained independent third-party valuation product as well as Loans with acceptable UCDP Risk Scores:

DUE DILIGENCE GRADING CRITERIA

Upon completion of the Loan file due diligence review, Clarifii assigned comprehensive grading that considers critical factors based on the specific review completed, in addition to product, clients, and rating agency requirements.

The National Recognized Statistical Rating Organizations (NRSRO) criteria referenced for this report and utilized for grading descriptions is based upon the NRSRO listed in the Asset-Backed Securities Form ABS Due Diligence-15E.

Final Event Grade

Credit Event Grade

Valuation Event Grade

Compliance Event Grade

CLARIFII DUE DILIGENCE RESULTS

Below are the final overall Loan grades for this review, as well as the credit, property valuation, and regulatory compliance component review grades.

Final Overall Loan Grade Results

The overall grade summary reflects the combination of the credit, property valuation and regulatory compliance component reviews into one overall grade. The overall grade assigned is the most severe grade from each of the component reviews.

Final Credit Component Grade Results

Final Property Valuation Grade Results

Final Regulatory Compliance Grade Results

ADDITIONAL LOAN SUMMARY DETAILS

Amortization Type

Occupancy

Loan Purpose

Lien Position

Original Term

DATA COMPARE RESULTS

Clarifii provided Clients with a copy of the Loan Level Data Compare Report which shows the differences between the data received by the sellers versus the data captured by Clarifii during the Loan review.

Summary of Data Compare Results

CLARIFII THIRD PARTY REPORTS DELIVERED

Clarifii furnished the following reports on this transaction:

Disclaimer

Clarifii LLC (“the Company”) performs due diligence reviews for Residential Mortgage-Backed Securities, as well as, assets, collateral, counterparty operations, and similar diligence reviews in the consumer finance industry.  In issuing reports and maintaining the ratings provided for herein, the Company relies on factual information it receives from issuers, underwriters, and from other sources which the Company reasonably believes to be credible.  The Company conducts reasonable investigation of the factual information relied upon by it in accordance with its ratings methodology.  The Company also makes reasonably good faith attempts to verify the information from independent sources (to the extent such sources are available).

Please be advised that Clarifii has not determined whether the Loans comply with federal, state, or local laws, constitutional provisions, regulations or ordinances, including, but not limited to, licensing and general usury laws that set rate and/or fee limitations, unless listed above. Clarifii’s review is focused on issues that raise concerns for secondary market investors and other assignees, based on potential for assignee liability, an adverse impact on the lien, and regulatory, litigation and headline risk. Clarifii’s review is not designed to fully test a lender’s compliance with all applicable disclosure and licensing requirements. The findings reached by Clarifii are dependent upon its receiving complete and accurate data regarding the Loans from Loan originators and other third parties. Please be further advised that Clarifii and its employees do not engage in the practice of law, and the findings set forth in the reports prepared by Clarifii do not constitute legal advice or opinions.

Ratings, analysis, reports, and other opinions (referred to collectively as “Reports”) issued by the Company are provided “as is” and without representation or warranty of any kind.  The Company hereby disclaims any representation or warranty (whether express or implied) as to accuracy, completeness, merchantability, or fitness for a particular purpose.  Reports are not a recommendation to buy, sell, or retain any security.  All reports are deemed jointly prepared, and no individual shall be exclusively deemed the “author” of any Report.  Individuals identified in a Report were involved in, but are not solely responsible for, the contents of any Report.

Unless expressly stated otherwise, Reports do not assess any risk other than credit risk.  In particular, any rating or grading in a Report does not take into consideration the risk of any security (or any portion thereof) due to changes in market conditions.

The Company does not provide investment, legal, or tax advice, and the Reports may not be construed as such.  Reports are issued for the benefit of the entity requesting the Report, only, and may not be used by third parties without the express written consent of the Company and the requesting party.  Reports are based on available information and current regulations as of the date of the Report, and the Company disclaims any obligation to update Reports due to a change of fact of regulation which occurs after the date of issuance. 

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