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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

(Mark one)

For the quarterly period ended March 31, 2015

OR

For the transition period from                      to                     

Commission file no. 0-16191

DEL TACO RESTAURANT PROPERTIES I

(A California limited partnership)

(Exact name of registrant as specified in its charter)

(949) 462-9300

(Registrant’s telephone number, including area code)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  x    No  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    Nox

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the registrant’s Form S-11 Registration Statement filed December 17, 1982 are incorporated by reference into Part IV of this report.

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INDEX

DEL TACO RESTAURANT PROPERTIES I

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DEL TACO RESTAURANT PROPERTIES I

CONDENSED BALANCE SHEETS

See accompanying notes to condensed financial statements.

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DEL TACO RESTAURANT PROPERTIES I

CONDENSED STATEMENTS OF INCOME

(Unaudited)

See accompanying notes to condensed financial statements.

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DEL TACO RESTAURANT PROPERTIES I

CONDENSED STATEMENTS OF CASH FLOWS

(Unaudited)

See accompanying notes to condensed financial statements.

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DEL TACO RESTAURANT PROPERTIES I

NOTES TO CONDENSED FINANCIAL STATEMENTS

FOR THE THREE MONTHS ENDED MARCH 31, 2015

(Unaudited)

NOTE 1 – BASIS OF PRESENTATION

The accompanying unaudited condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by accounting principles generally accepted in the United States of America for complete financial statements and should therefore be read in conjunction with the financial statements and notes thereto contained in the annual report on Form 10-K for the year ended December 31, 2014 for Del Taco Restaurant Properties I (the Partnership or the Company). In the opinion of management, all adjustments (consisting of normal recurring accruals) necessary to present fairly the Partnership’s financial position at March 31, 2015 and the results of operations and cash flows for the three month periods ended March 31, 2015 and 2014 have been included. Operating results for the three months ended March 31, 2015 are not necessarily indicative of the results that may be expected for the year ending December 31, 2015. Amounts related to disclosure of December 31, 2014 balances within these condensed financial statements were derived from the 2014 audited financial statements.

Management has evaluated events subsequent to March 31, 2015 through the date that the accompanying condensed financial statements were filed with the Securities and Exchange Commission for transactions and other events which may require adjustment of and/or disclosure in such financial statements.

NOTE 2 – NET INCOME PER LIMITED PARTNERSHIP UNIT

Net income per limited partnership unit is based on net income attributable to the limited partners (after 1% allocation to the general partner) using the weighted average number of units outstanding during the periods presented, which amounted to 8,751 in 2015 and 2014.

Pursuant to the partnership agreement, annual partnership net income is allocated one percent to Del Taco LLC, formerly known as Del Taco, Inc., (Del Taco or the General Partner) and 99 percent to the limited partners. A partnership net loss in any year will be allocated 24 percent to the General Partner and 76 percent to the limited partners until the losses so allocated equal income previously allocated. Any additional losses will be allocated one percent to the General Partner and 99 percent to the limited partners. Partnership gains from any sale or refinancing will be allocated one percent to the General Partner and 99 percent to the limited partners until allocated gains and profits equal losses. Additional gains will be allocated 24 percent to the General Partner and 76 percent to the limited partners.

NOTE 3 – LEASING ACTIVITIES

The Partnership leases six properties for operation of restaurants to Del Taco on a triple net basis. One property has been subleased to a Del Taco franchisee. The leases are for terms of 35 years commencing with the completion of the restaurant facility located on each property and require monthly rentals equal to 12 percent of the gross sales of the restaurants. The leases expire in the years 2020 to 2021.

Pursuant to the lease agreements, minimum rentals of $3,500 per month are due to the Partnership during the first six months of any non-operating period caused by an insured casualty loss.

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DEL TACO RESTAURANT PROPERTIES I

NOTES TO CONDENSED FINANCIAL STATEMENTS – CONTINUED

FOR THE THREE MONTHS ENDED MARCH 31, 2015

(Unaudited)

NOTE 3 – LEASING ACTIVITIES – continued

For the three months ended March 31, 2015, the five restaurants operated by Del Taco, for which the Partnership is the lessor, had combined, unaudited sales of $1,504,262 and unaudited net income of $31,680 as compared to unaudited sales of $1,360,037 and unaudited net losses of $11,733, respectively, for the corresponding period in 2014. Net income or loss of each restaurant includes charges for general and administrative expenses incurred in connection with supervision of restaurant operations and interest expense and the increase in net income from the corresponding period of the prior year primarily relates to increases in sales. For the three months ended March 31, 2015, the one restaurant operated by a Del Taco franchisee, for which the Partnership is the lessor, had unaudited sales of $241,156 as compared with $220,788 during the same period in 2014.

NOTE 4 – TRANSACTIONS WITH DEL TACO

The receivable from Del Taco consists primarily of rent accrued for the month of March 2015. The March rent receivable was collected in April 2015.

Del Taco serves in the capacity of general partner in other partnerships which are engaged in the business of operating restaurants, and three other partnerships which were formed for the purpose of acquiring real property in California for construction of Mexican-American restaurants for lease under long-term agreements to Del Taco for operation under the Del Taco trade name.

In addition, see Note 5 with respect to certain distributions to the General Partner.

NOTE 5 – DISTRIBUTIONS

Total cash distributions declared and paid in February 2015 were $173,188. On April 23, 2015, a distribution to the limited partners of $122,822, or approximately $14.04 per limited partnership unit, was approved. Such distribution was paid on May 7, 2015. The General Partner also received a distribution of $1,241 with respect to its 1% partnership interest in May 2015.

NOTE 6 – PAYABLE TO LIMITED PARTNERS

Payable to limited partners represents a reclassification from cash for distribution checks made to limited partners that have remained outstanding for six months or longer.

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DEL TACO RESTAURANT PROPERTIES I

NOTES TO CONDENSED FINANCIAL STATEMENTS – CONTINUED

FOR THE THREE MONTHS ENDED MARCH 31, 2015

(Unaudited)

NOTE 7 – CONCENTRATION OF RISK

The six restaurants leased to Del Taco make up all of the income producing assets of the Partnership and contributed all of the Partnership’s rental revenues during the three months ended March 31, 2015 and 2014. Therefore, the business of the Partnership is entirely dependent on the success of the Del Taco trade name restaurants that lease the properties.

The Partnership maintains substantially all of its cash and cash equivalents at one major commercial bank. Although the Partnership at times maintains balances that exceed the federally insured limit, it has not experienced any losses related to these balances and management believes the credit risk to be minimal.

NOTE 8 – COMMUNICATION FROM CERTAIN LIMITED PARTNERS AND STRAW POLL RESULTS

During the third quarter of 2014, several limited partners communicated to the General Partner their desire to potentially sell all of the properties and then dissolve the Partnership. Pursuant to the Partnership agreement, any decision to sell all of the properties and to dissolve the Partnership would require approval from a majority in interest of limited partners. On October 1, 2014 the General Partner initiated a “straw poll” of all limited partners to determine if there is sufficient interest to support a potential sale of the properties and dissolution of the Partnership, as disclosed in Form 8-K filed on October 1, 2014. Limited partner responses to the straw poll were received during the fourth quarter of 2014 and on December 17, 2014, Del Taco filed a Form 8-K to disclose the results of the poll. The poll was intended to gauge interest level only and the results indicate a strong majority of the units responded either “open to” or “strongly in favor of” Del Taco testing the market and presenting a sale proposal to the limited partners for a vote. Accordingly, Del Taco filed a Form 8-K on January 12, 2015 indicating its intention to initiate a sale process to market the properties owned by the Partnership that may result in the presentation of a sale transaction to the limited partners for approval. Del Taco intended to appoint a special committee comprised of a small group of qualified limited partners to facilitate the sale process and to manage any potential conflicts of interest with respect to Del Taco that may arise during the sale process, however, only one timely application was received. Del Taco does not believe one committee member could adequately perform the role required by the committee, and therefore, the sale process has commenced without a special committee and Del Taco will resolve any potential conflicts of interest pursuant to the Partnership’s partnership agreement and applicable law.

On February 17, 2015, MacKenzie Realty Capital, Inc. (“MacKenzie”), a limited partner, filed a schedule TO initiating a tender offer to purchase all units of the Partnership. The MacKenzie tender offer is unrelated to the sale process that Del Taco has initiated. On February 27, 2015, the Partnership filed a Schedule 14D-9 solicitation/recommendation statement in response to the Schedule TO.

On March 16, 2015, after evaluating several alternatives the General Partner engaged CBRE, Inc. (“CBRE”) as its commercial real estate broker to conduct a process to market the properties owned by the Partnership. The General Partner expects to evaluate offers; however, there are no assurances that Del Taco will receive any acceptable offers or will be successful in entering into a binding agreement to sell the properties.

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Liquidity and Capital Resources

Del Taco Restaurant Properties I (the Partnership or the Company) offered limited partnership units for sale between March 1983 and March 1984. $4,375,500 was raised through the sale of limited partnership units and used to acquire sites and build six restaurants and also to pay commissions to brokers and to reimburse Del Taco LLC (the General Partner or Del Taco) for offering costs incurred.

The six restaurants leased to Del Taco make up all of the income producing assets of the Partnership. Therefore, the business of the Partnership is entirely dependent on the success of the Del Taco trade name restaurants that lease the properties. The success of the restaurants is dependent on a large variety of factors, including, but not limited to, competition, consumer demand and preference for fast food, in general, and for Mexican-American food in particular.

Results of Operations

The Partnership owns six properties that are under long-term lease to Del Taco for restaurant operations (Del Taco, in turn, has subleased one of the restaurants to a Del Taco franchisee).

The following table sets forth rental revenue earned by restaurant (unaudited):

The Partnership receives rental revenues equal to 12 percent of gross sales from the restaurants. The Partnership earned rental revenue of $209,450 during the three month period ended March 31, 2015, which represents an increase of $19,751 from the corresponding period in 2014. The changes in rental revenues between 2015 and 2014 are directly attributable to changes in sales levels at the restaurants under lease due to local competitive and industry factors.

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The following table breaks down general and administrative expenses by type of expense:

Prior year percentages above have been reclassified to conform to the March 31, 2015 presentation. General and administrative expenses increased due to increased legal and printing costs in connection with the matter described in Note 8.

For the three month period ended March 31, 2015, net income increased by $2,420 from 2014 to 2015 due to the increase in revenues of $19,751 and the increase in interest and other income of $342, partially offset by the increase in general and administrative expenses of $17,673.

Significant Recent Accounting Pronouncements

None.

Off-Balance Sheet Arrangements

None.

Critical Accounting Policies and Estimates

The Partnership’s consolidated interim financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America. The preparation of the financial statements requires significant management judgments, assumptions and estimates about matters that are inherently uncertain. These judgments affect the reported amounts of assets and liabilities and the Partnership’s disclosure of contingent assets and liabilities as of the dates of the financial statements and the reported amounts of revenue and expenses during the reporting periods. With different estimates or assumptions, materially different amounts could be reported in the financial statements. Additionally, other companies may utilize different estimates that may impact the comparability of the Partnership’s results of operations to those of companies in similar businesses. A discussion of the accounting policies that management considers critical which involve significant management judgments, assumptions and estimates is included in the Partnership’s Annual Report on Form 10-K for the year ended December 31, 2014. There have been no significant changes to the Partnership’s policies during 2015.

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None.

As of the end of the period covered by this quarterly report, we carried out an evaluation, under the supervision and with the participation of the Company’s management, including the Company’s Chief Executive Officer and Chief Financial Officer, of the effectiveness of the design and operation of the Company’s disclosure controls and procedures. Based upon that evaluation, the Chief Executive Officer and Chief Financial Officer concluded that the Company’s disclosure controls and procedures are effective in timely alerting them to material information relating to the Company required to be included in the Company’s periodic Securities and Exchange Commission filings.

There were no significant changes in the Company’s internal controls over financial reporting that occurred during our most recent fiscal quarter that materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

Not applicable.

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There is no information required to be reported for any items under Part II, except as follows:

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SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

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