WPP WPP PLC

NOTES TO FINANCIAL STATEMENTS

AS OF APRIL 1, 2016 (DATE OF ASSET TRANSFER) AND DECEMBER 31, 2015

The following description of The M Plan (the “Plan”), as amended and restated effective January 1, 2010, is provided for general information purposes only. Participants should refer to the Plan document for a more complete description of the Plan’s provisions.

General

The Plan is a defined contribution plan, subject to the provisions of the Employee Retirement Income Security Act of 1974 (“ERISA”). Mercer HR Services, LLC (“Trustee”) is the Trustee and Recordkeeper of the Plan.

The Plan was established effective January 1, 2001. Effective August 1, 2003, the Plan name was changed from the “MyShare Retirement Plan” to “The M Plan.” The Plan is a defined contribution 401(k) plan sponsored by GroupM Worldwide, LLC (the “Company”), a wholly-owned subsidiary of WPP plc. The Plan covers substantially all employees of GroupM Worldwide, LLC, Mindshare USA, LLC, MAXUS Communications, LLC, Mediaedge:CIA, LLC, Mediacom Worldwide, LLC, ESP Properties LLC, Catalyst Online, LLC, The Midas Exchange, Inc., Xaxis, Inc., Metavision Media LLC, MSIX Communications LLC, Action Exchange Inc., Medialets WW LLC, and Gain Theory LLC (each an indirect wholly-owned subsidiary of WPP plc, each a participating “Employer” and collectively the participating “Employers”), who have attained age 18. The Retirement Plan Committee of the Company controls and manages the operation and administration of the Plan.

Effective April 1, 2016, the Company became a participating employer in the Savings and Investment Plan (“SIP”), a plan sponsored by WPP Group, USA, Inc. (“WPP”). All assets of the Plan representing all participant account balances were transferred to the SIP on April 1, 2016.

Contributions/Eligibility

Deferred Contributions

Participants may contribute up to 50% of their pretax annual compensation, as defined by the Plan. Participants may also contribute amounts representing distributions from other qualified defined contribution plans.

For Plan years 2016 and 2015, eligible compensation is limited to $265,000.

Matching Contributions

The Company and each participating Employer may contribute a matching contribution equal to 50% of the first 6% of compensation that a participant contributes to the Plan. Additional matching contributions may be contributed at the discretion of each participating Employer. All contributions are subject to Internal Revenue Code (“IRC”) limitations.

Catch-up Contributions

Participating employees who have attained age 50 may contribute an additional percentage of eligible compensation as catch-up contributions (up to the annual federal dollar limit for these contributions).

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THE M PLAN

NOTES TO FINANCIAL STATEMENTS

AS OF APRIL 1, 2016 (DATE OF ASSET TRANSFER) AND DECEMBER 31, 2015

Profit Sharing Contributions

Each year the Company and each participating Employer, at its discretion, may contribute a profit sharing contribution. A participant is eligible to participate in the profit sharing contribution component of the Plan on the first day of the month following one year of continuous service, and a participant must be employed on the last day of the Plan year in order to receive the profit sharing contribution.

Participant Accounts

Each participant’s account is credited with the participant’s contributions, the Employer’s matching and profit sharing contributions, and investment earnings. Individual accounts are charged with withdrawals, Plan losses and an allocation of administrative expenses. The benefit to which a participant is entitled is the benefit that can be provided from the participant’s vested account balance.

Investments

Participants direct the investment of their account balances from among various investment options offered under the Plan. The Plan offered a number of mutual funds, a common collective trust fund, and a WPP Stock Fund, which invests in American Depositary Shares of WPP plc (“WPP plc ADSs”).

Vesting

Participants are vested immediately in their own contributions plus actual earnings thereon. Participants are 100% vested in both their profit sharing contributions and matching contributions after 3 years of service.

Forfeited Accounts

At December 31, 2015, forfeited non-vested amounts totaled approximately $1,051,000. In accordance with Plan provisions, these amounts may be used to reduce Company contributions (Profit Sharing or Matching) or Plan expenses. During the period ended April 1, 2016, forfeitures of $180,504 were used to fund a portion of the 2015 matching contributions. Forfeitures of $1,056,058 were transferred to the SIP on April 1, 2016, which were included in net assets transferred out in the Statement of Changes in Net Assets Available for Benefits.

Notes Receivable from Participants

Participants may borrow from their fund accounts a minimum of $1,000 up to a maximum equal to the lesser of $50,000, or 50% of their vested account balance. The notes are secured by the balance in the participant’s account and bear interest at rates commensurate with local prevailing rates as determined quarterly by the Plan Administrator.

Payment of Benefits

Upon termination of employment due to death, disability, or retirement, a participant may elect to receive either a lump-sum amount equal to the value of the participant’s vested interest in his or her account, or annual installments over a period not exceeding the life expectancy of the participant or the participant’s designated beneficiary. The Company may distribute participant account balances in a lump-sum without consent to terminated participants whose vested account balances are $1,000 or less.

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THE M PLAN

NOTES TO FINANCIAL STATEMENTS

AS OF APRIL 1, 2016 (DATE OF ASSET TRANSFER) AND DECEMBER 31, 2015

Basis of Accounting

The financial statements of the Plan are prepared on the accrual basis of accounting in accordance with accounting principles generally accepted in the United States of America (“GAAP”).

Investments held by a defined contribution plan are required to be reported at fair value, except for fully benefit-responsive investment contracts. Contract value is the relevant measure for the portion of the net assets available for benefits of a defined contribution plan attributable to fully benefit-responsive investment contracts because contract value is the amount participants normally would receive if they were to initiate permitted transactions under the terms of the Plan.

Investment Valuation and Income Recognition

The Plan’s investments are reported at fair value. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.

Purchases and sales of securities are recorded on a trade-date basis. Interest income is recorded on the accrual basis. Dividends are recorded on the ex-dividend date. Net appreciation/depreciation includes the Plan’s gains and losses on investments bought and sold as well as held during the year.

Use of Estimates

The preparation of financial statements in accordance with GAAP requires Plan management to make estimates and assumptions that affect the reported amounts of assets and liabilities and changes therein, and disclosure of contingent assets and liabilities. Actual results could differ from those estimates.

Notes Receivable from Participants

Notes receivable from participants are measured at their unpaid principal balance plus any accrued but unpaid interest. Interest income is recorded on the accrual basis. Related fees are charged directly to the borrowing participant’s account and are included in administrative expenses when incurred. No allowance for credit losses has been recorded as of April 1, 2016 and December 31, 2015. If a participant does not make note repayments and the Plan Administrator considers the participant note to be in default, the note balance is reduced, and the delinquent participant note receivable is recorded as a benefit payment based on the terms of the Plan document.

Excess Contributions Payable

Amounts payable to participants for contributions in excess of amounts allowed by the Internal Revenue Service (“IRS”) are recorded as a liability with a corresponding reduction to contributions. There were no excess contributions for the period ended April 1, 2016 or for the year ended December 31, 2015.

Payment of Benefits

Benefits are recorded when paid.

Administrative Expenses

Certain expenses of maintaining the Plan are paid by the Plan, unless otherwise paid by the Company. Expenses that are paid by the Company are excluded from these financial statements. Fees related to the administration of notes receivable from participants are charged directly to the participant’s account and are included in administrative expenses. Investment related expenses are included in net appreciation/depreciation of fair value of investments.

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THE M PLAN

NOTES TO FINANCIAL STATEMENTS

AS OF APRIL 1, 2016 (DATE OF ASSET TRANSFER) AND DECEMBER 31, 2015

Subsequent Events

The Plan’s management evaluated subsequent events through September 23, 2016, the date the financial statements were available to be issued, and no additional disclosures were required.

The framework for measuring fair value provides a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). The three levels of the fair value hierarchy under the FASB Accounting Standards Codification (ASC) 820 are described as follows: Level 1 inputs consist of unadjusted quoted prices for identical assets or liabilities in active markets that the Plan has the ability to access; Level 2 inputs include quoted prices for similar assets or liabilities in active markets, quoted prices in markets that are not active, inputs other than quoted prices that are observable for the asset or liability, or other inputs that are derived principally from, or corroborated by, observable market data by correlation or other means. If the asset or liability has a specified (contractual) term, the Level 2 input must be observable for substantially the full term of the asset or liability. Level 3 inputs are unobservable and significant to the fair value measurement.

The asset or liability’s fair value measurement level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Valuation techniques maximize the use of relevant observable inputs and minimize the use of unobservable inputs.

The following is a description of the valuation methodologies used for investments measured at fair value.

Mutual Funds

The mutual funds are valued at the daily closing price as reported by the fund. Mutual funds held by the Plan are open-end mutual funds that are registered with the Securities and Exchange Commission. These funds are required to publish their daily net asset value (“NAV”) and to transact at that price. The mutual funds held by the Plan are deemed to be actively traded.

WPP Stock Fund

The fair value of the WPP Stock Fund is based on quoted NAV’s of the shares held by the Plan at year-end.

The Morley Stable Value Fund

The Morley Stable Value Fund (“MSVF”), a common collective trust, invests directly or indirectly in fully benefit–responsive investment contracts. The MSVF is valued at the NAV as provided by the trustee, which is used as a practical expedient to estimate fair value. This practical expedient would not be used if it is determined to be probable that the fund will sell the investment for an amount different from the reported NAV. Participant transactions (purchases and sales) may occur daily. Were the Plan to initiate a full redemption of the MSVF, the issuer reserves the right to temporarily delay withdrawal from the MSVF in order to ensure that securities liquidations will be carried out in an orderly business manner. The MSVF, included in the fair value hierarchy table below, files a U.S. Department of Labor Form 5500, Annual Return/Report of Employee Benefit Plan, as a direct filing entity. Accordingly, certain disclosure requirements under ASU-2015-12 with respect to investments strategies for investments measured using the net asset value practical expedient are not required in this report.

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THE M PLAN

NOTES TO FINANCIAL STATEMENTS

AS OF APRIL 1, 2016 (DATE OF ASSET TRANSFER) AND DECEMBER 31, 2015

The following table sets forth by level, within the fair value hierarchy, the Plan’s investments at fair value as of December 31, 2015. There were no assets held at April 1, 2016.

Gains and losses included in changes in net assets available for benefits for the period ended April 1, 2016 are reported in net appreciation/depreciation in fair value of investments.

The IRS has determined and informed the Company by a letter dated August 1, 2012, that the Plan and related Trust are designed in accordance with applicable sections of the IRC. Although the Plan has been amended since receiving the determination letter, the Plan Administrator believes that the Plan is designed, and is currently being operated, in compliance with the applicable requirements of the IRC and, therefore, believes that the Plan is qualified and the related Trust is tax-exempt.

GAAP requires Plan management to evaluate tax positions taken by the Plan and recognize a tax liability if the Plan has taken an uncertain position that more likely than not would not be sustained upon examination by the IRS. The Plan is subject to routine audits by taxing jurisdictions; however, there are currently no audits for any tax periods in progress. The Plan Administrator believes it is no longer subject to income tax examinations for years prior to 2013.

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THE M PLAN

NOTES TO FINANCIAL STATEMENTS

AS OF APRIL 1, 2016 (DATE OF ASSET TRANSFER) AND DECEMBER 31, 2015

The Plan provides participants the option to invest in the WPP Stock Fund, a party-in-interest. At December 31, 2015 the Plan held 63,673 WPP Group plc ADSs in the WPP Stock Fund valued at $7,305,794. These transactions qualify as exempt party-in-interest transactions. There have been no known prohibited transactions with parties-in-interest.

Fees incurred by the Plan for the investment management services from the Trustee were $218,691 for the period ended April 1, 2016.

Although it has not expressed any intent to do so, the Company has the right under the Plan to discontinue its contributions at any time and to terminate the Plan subject to the provisions of ERISA. In the event of Plan termination, participants would become 100% vested in their employer contributions.

The Plan invests in various investment securities. Investment securities are exposed to various risks, such as interest rate, market, and credit risks. Due to the level of risk associated with certain investment securities, it is at least reasonably possible that changes in the values of investment securities will occur in the near term and that such changes could materially affect participants’ account balances and the amounts reported in the Statements of Net Assets Available for Benefits.

On April 1, 2016, all assets of the Plan, representing all participant account balances in the amount of $272,249,422, were transferred out to the SIP, a tax-qualified retirement plan sponsored by an affiliate of the Plan sponsor.

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See accompanying Report of Independent Registered Public Accounting Firm.

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