Merrill Lynch Depositor Inc. 6.0518% Index Plus Trust Series 2003-1 (IPB) 10-K 2023 FY Annual report

EXHIBIT 31.1

I, Matthew J. Nelson, certify that:

1. I have reviewed this annual report on Form 10-K, and all reports on Form 8-K containing distribution or servicing reports filed in respect of periods included in the year covered by this annual report, of Merrill Lynch Depositor, Inc., on behalf of INDEXPLUS Trust Series 2003-1;

2. Based on my knowledge, the information in these reports, taken as a whole, does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading as of the last day of the period covered by this annual report;

3. Based on my knowledge, the distribution or servicing information required to be provided to the depositor by the trustee under the pooling and servicing, or similar, agreement, for inclusion in these reports is included in these reports;

4. I am responsible for reviewing the activities performed by the depositor and the trustee under the pooling and servicing, or similar, agreement and based upon my knowledge and the annual compliance review required under that agreement, and except as disclosed in the reports, the depositor and trustee have each fulfilled its obligations under that agreement; and

5. The reports disclose all significant deficiencies relating to the compliance by the depositor or trustee with the minimum servicing or similar standards based upon the report provided by an independent public accountant, after conducting a review in compliance with the Uniform Single Attestation Program for Mortgage Bankers or similar procedure, as set forth in the pooling or servicing, or similar, agreement, that is included in these reports.

In giving the certifications above, I have reasonably relied on information provided to me by the following unaffiliated parties: The Bank of New York Mellon and its officers and agents.

Date: March 22, 2024	/s/ Matthew J. Nelson
	Matthew J. Nelson
	President