NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION IN WHOLE OR IN PART, IN, INTO OR FROM ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OF SUCH JURISDICTION

FOR IMMEDIATE RELEASE

7 December 2023

RECOMMENDED CASH ACQUISITION

of

ONTHEMARKET PLC ("OnTheMarket" or the "Company")

by

COSTAR UK LIMITED ("CoStar UK"),

a wholly-owned, indirect subsidiary

of

COSTAR GROUP, INC. ("CoStar")

COURT SANCTION OF SCHEME OF ARRANGEMENT, EXERCISE OF OPTIONS AND ADMISSION TO TRADING ON AIM, SUSPENSION OF DEALINGS AND RULE 2.9 ANNOUNCEMENT

On 19 October 2023, the Boards of CoStar UK and OnTheMarket announced that they had reached agreement on the terms of a recommended all cash offer pursuant to which CoStar UK, a wholly-owned, indirect subsidiary of CoStar, would acquire the entire issued and to be issued share capital of OnTheMarket (the "Acquisition"). The Acquisition is being effected by means of a Court-sanctioned scheme of arrangement under Part 26 of the Companies Act 2006 (the "Scheme"), full details of which were sent, or made available, to the shareholders of OnTheMarket in the circular dated 7 November 2023 (the "Scheme Document").

On 4 December 2023, the Scheme was approved by the requisite majorities of Scheme Shareholders at the Court Meeting and the Special Resolution in connection with the implementation of the Scheme was passed by the requisite majority of OnTheMarket Shareholders at the General Meeting.

Capitalised terms used and not defined in this announcement have the meanings given to them in the Scheme Document.

Sanction of the Scheme

The Boards of OnTheMarket and CoStar UK are pleased to announce that, on 7 December 2023, the High Court of Justice in England and Wales made an order sanctioning the Scheme under section 899 of the Companies Act.

The Scheme will become Effective upon the delivery of a copy of the Court Order to the Registrar of Companies, which is expected to occur on 12 December 2023.

Next steps

In order to satisfy the exercise of certain OnTheMarket Share Awards under the OnTheMarket Share Plans with effect from, or immediately prior to (as the case may be), the sanction of the Scheme by the Court, including by certain persons discharging managerial responsibilities ("PDMRs") of the Company (as set out in the disclosures below), the Company has allotted and issued, subject to the Scheme being sanctioned by the Court, 4,903,471 OnTheMarket Shares to the OnTheMarket EBT Trustee (the "First Tranche OnTheMarket Share Award Shares").

Application for admission of the First Tranche OnTheMarket Share Award Shares to trading on AIM ("First Admission") has been made and admission is expected to occur at 8.00 a.m. on 11 December 2023. The First Tranche OnTheMarket Share Award Shares will rank pari passu with the OnTheMarket Shares in issue at such time.

OnTheMarket confirms that the last day of dealings in, and for registrations of transfers of, OnTheMarket Shares (including the First Tranche OnTheMarket Share Award Shares) will be 11 December 2023 and the Scheme Record Time will be 6.00 p.m. on 11 December 2023. Scheme Shareholders on OnTheMarket's register of members at the Scheme Record Time will, upon the Scheme becoming Effective, be entitled to receive the consideration under the Scheme.

Dealings in OnTheMarket Shares (including the First Tranche OnTheMarket Share Award Shares) on AIM will be suspended from 7:30 a.m. on 12 December 2023. The suspension is made pursuant to OnTheMarket's application to the London Stock Exchange and is being effected as part of the Scheme.

In addition, in order to satisfy the exercise of certain additional OnTheMarket Share Awards under the OnTheMarket Share Plans on the day immediately following the Effective Date, the Company has allotted and issued, subject to and conditional upon the Scheme becoming Effective, 269,478 OnTheMarket Shares to the OnTheMarket EBT Trustee (the "Second Tranche OnTheMarket Share Award Shares").

Application for admission of the Second Tranche OnTheMarket Share Award Shares to trading on AIM ("Second Admission") has been made and admission is expected to occur at 8.00 a.m. on 13 December 2023. The Second Tranche OnTheMarket Share Award Shares will rank pari passu with the OnTheMarket Shares in issue at such time. The Second Tranche OnTheMarket Share Award Shares will be acquired by CoStar UK pursuant to the relevant provisions in the Amended OnTheMarket Articles.

It is further expected that, subject to the Scheme becoming Effective on 12 December 2023, the cancellation of admission to trading of OnTheMarket Shares on AIM will take effect from 7:00 a.m. on 14 December 2023.

A further announcement will be made when the Scheme becomes Effective.

Rule 2.9 disclosure and total voting rights

In accordance with Rule 2.9 of the City Code on Takeovers and Mergers (the "Code"), on First Admission, OnTheMarket will have in issue 85,111,256 ordinary shares of 0.2 pence each ("OnTheMarket Shares") with no OnTheMarket Shares held in treasury. The International Securities Identification Number ("ISIN") for the OnTheMarket Shares is GB00BFN3K335.

This figure of 85,111,256 OnTheMarket Shares may also be used by shareholders, from First Admission, as the denominator for the calculations by which they will determine if they are required to notify their interest in, or a change to their interest in, the share capital of the Company under the FCA's Disclosure Guidance and Transparency Rules.

On Second Admission, OnTheMarket will have in issue 85,380,734 OnTheMarket Shares with no OnTheMarket Shares held in treasury.

This figure of 85,380,734 OnTheMarket Shares may also be used by shareholders, from Second Admission, as the denominator for the calculations by which they will determine if they are required to notify their interest in, or a change to their interest in, the share capital of the Company under the FCA's Disclosure Guidance and Transparency Rules.

Notification and public disclosure of transactions by persons discharging managerial responsibilities and persons closely associated with them

General

All references in this announcement to times are to London time unless otherwise stated. The expected timetable of principal events for the implementation of the Scheme remains as set out in the results of Court Meeting and the General Meeting announcement released on 4 December 2023. The dates and times given are indicative only and are based on OnTheMarket's current expectations and may be subject to change (including as a result of changes to the regulatory timetable). If any of the expected times and/or dates change, the revised times and/or dates will be notified to OnTheMarket Shareholders by announcement through a Regulatory Information Service.

Save where otherwise defined herein, capitalised terms and expressions used in this announcement have the meanings given to them in the Scheme Document.

Enquiries

Important notices

Zeus Capital Limited ("Zeus"), which is authorised and regulated in the United Kingdom by the FCA, is acting as Rule 3 adviser, joint financial adviser, nominated adviser and joint corporate broker to OnTheMarket and no one else in connection with the matters referred to in this announcement and will not regard any other person as its client in relation to such matters and will not be responsible to anyone other than OnTheMarket for providing the protections afforded to clients of Zeus, nor for providing advice in relation to any matter referred to in this announcement. Neither Zeus nor any of its affiliates owes or accepts any duty, liability or responsibility whatsoever (whether direct or indirect, whether in contract, in tort, under statute or otherwise) to any person who is not a client of Zeus in connection with the matters referred to in this announcement, any statement contained herein or otherwise.

Shore Capital and Corporate Limited and Shore Capital Stockbrokers Limited (together or individually, "Shore Capital"), which are authorised and regulated in the United Kingdom by the FCA, are acting as joint financial adviser and joint corporate broker to OnTheMarket and no one else in connection with the matters referred to in this announcement and will not regard any other person as their client in relation to such matters and will not be responsible to anyone other than OnTheMarket for providing the protections afforded to clients of Shore Capital, nor for providing advice in relation to any matter referred to in this announcement. Neither Shore Capital nor any of their affiliates owes or accepts any duty, liability or responsibility whatsoever (whether direct or indirect, whether in contract, in tort, under statute or otherwise) to any person who is not a client of Shore Capital in connection with the matters referred to in this announcement, any statement contained herein or otherwise.

Goldman Sachs International, which is authorised by the Prudential Regulation Authority and regulated by the FCA and the Prudential Regulation Authority in the United Kingdom, and Goldman Sachs & Co. LLC, which is regulated by FINRA, are acting exclusively for CoStar and CoStar UK as financial advisers and no one else in connection with the matters referred to in this announcement and will not be responsible to anyone other than CoStar and CoStar UK for providing the protections afforded to clients of Goldman Sachs, or for providing advice in relation to the matters referred to in this announcement. None of Goldman Sachs International, Goldman Sachs & Co. LLC or any of their respective subsidiaries, affiliates or branches, nor their respective partners, directors, officers employees or agents owes or accepts any duty, liability or responsibility whatsoever (whether direct, indirect, consequential, whether in contract, in tort, under statute or otherwise) to any person who is not a client of Goldman Sachs International or Goldman Sachs & Co. LLC in connection with this announcement, any statement contained herein or otherwise.

Further information

This announcement is for information purposes only and is not intended to and does not constitute, or form any part of, an offer to sell or subscribe for or any invitation to purchase or subscribe for any securities or the solicitation of any vote or approval in any jurisdiction pursuant to the Acquisition or otherwise. The Acquisition is being implemented solely through and on the terms set out in the Scheme Document and the accompanying Forms of Proxy (or, in the event that the Acquisition is to be implemented by means of a Takeover Offer, the Offer Document and form of acceptance), which contains the full terms and conditions of the Acquisition. Any approval, decision or other response to the Acquisition should be made only on the basis of the information in the Scheme Document (or if the Acquisition is implemented by way of a Takeover Offer, the Offer Document). OnTheMarket Shareholders are strongly advised to read the formal documentation in relation to the Acquisition.

This announcement does not constitute a prospectus or prospectus exempted document.

The statements contained in this announcement are made as at the date of this announcement, unless some other time is specified in relation to them, and the publication of this announcement shall not give rise to any implication that there has been no change in the facts set forth in this announcement since such date.

Overseas Shareholders

This announcement has been prepared for the purpose of complying with English law, the AIM Rules, the Code and the Market Abuse Regulation and the information disclosed may not be the same as that which would have been disclosed if this announcement had been prepared in accordance with the laws of jurisdictions outside the United Kingdom.

The release, publication or distribution of this announcement in jurisdictions other than the United Kingdom may be restricted by law and/or regulations and such laws and/or regulations may affect the availability of the Acquisition to persons who are not resident in the United Kingdom. Persons who are not resident in the United Kingdom, or who are subject to laws of any jurisdiction other than the United Kingdom, should inform themselves about, and observe, any applicable requirements. Any failure to comply with the applicable legal or regulatory requirements may constitute a violation of the laws and/or regulations of any such jurisdiction. To the fullest extent permitted by applicable law, the companies and persons involved in the Acquisition disclaim any responsibility and liability for the violation of such restrictions by any person.

Any person (including, without limitation, nominees, trustees and custodians) who would, or otherwise intends to, forward this announcement, the Scheme Document or any accompanying document(s) to any jurisdiction outside the United Kingdom should refrain from doing so and seek appropriate professional advice before taking any action. The Acquisition will be subject to the applicable requirements of the Code, the Takeover Panel, the London Stock Exchange (including the AIM Rules) and the FCA.

Unless otherwise determined by CoStar and/or CoStar UK or required by the Code, and permitted by applicable law and regulation, the Acquisition will not be made, directly or indirectly, in or into or by use of the mails or any other means or instrumentality (including, without limitation, telephonic or electronic) of interstate or foreign commerce of, or any facility of a national, state or other securities exchange of, a Restricted Jurisdiction, and no person may vote in favour of the Scheme, and any Takeover Offer will not be capable of acceptance, by any such use, means, instrumentality or facility or from within a Restricted Jurisdiction. Accordingly, copies of this announcement and the formal documentation relating to the Acquisition are not being, and must not be, directly or indirectly, mailed or otherwise forwarded or distributed in, into or from a Restricted Jurisdiction and persons receiving this announcement (including custodians, nominees and trustees) must not distribute or send it into or from a Restricted Jurisdiction.

In the event that the Acquisition is implemented by way of a Takeover Offer and extended into the US, CoStar UK will do so in satisfaction of the procedural and filing requirements of the US securities laws at that time, to the extent applicable thereto.

The Acquisition relates to the shares of a company incorporated in England and it is proposed to be made by means of a scheme of arrangement provided for under English law. A transaction effected by means of a scheme of arrangement is not subject to the shareholder vote, proxy solicitation and tender offer rules under the US Exchange Act. Accordingly, the Scheme is subject to the disclosure requirements and practices applicable in the UK to schemes of arrangement, which differ from the disclosure requirements and practices of US shareholder vote, proxy solicitation and tender offer rules.

If CoStar UK were to elect to implement the Acquisition by means of a Takeover Offer, such Takeover Offer shall be made in compliance with all applicable laws and regulations, including section 14(e) of the US Exchange Act and Regulation 14E thereunder. Such Takeover Offer would be made in the US by CoStar UK and no one else.

In addition to any such Takeover Offer, CoStar UK, certain affiliated companies and the nominees or brokers (acting as agents) of CoStar UK and/or such affiliated companies may make certain purchases of, or arrangements to purchase, OnTheMarket Shares outside such Takeover Offer during the period in which such Takeover Offer would remain open for acceptance. If such purchases or arrangements to purchase are made, they would be made outside the United States in compliance with applicable law, including the US Exchange Act.

The receipt of cash consideration by an OnTheMarket Shareholder for the transfer of their OnTheMarket Shares pursuant to the Scheme will be a taxable transaction for United States federal income tax purposes and under applicable US state and local, as well as overseas and other, tax laws. In certain circumstances, OnTheMarket Shareholders that are not US persons and that receive cash consideration pursuant to the Scheme may be subject to US withholding tax. Each OnTheMarket Shareholder is urged to consult an independent professional adviser regarding the applicable tax consequences of the Acquisition, including under applicable United States, state and local, as well as overseas and other tax laws.

Financial information relating to OnTheMarket included in this announcement or included in the Scheme Document has been prepared in accordance with accounting standards applicable in the United Kingdom and may not be comparable to the financial statements of US companies or companies whose financial statements are prepared in accordance with generally accepted accounting principles in the United States ("US GAAP"). US GAAP differs in certain significant respects from accounting standards applicable in the United Kingdom.

It may be difficult for a US-based investor to enforce their rights and any claim they may have arising under US securities laws since the Scheme relates to the shares of a company incorporated under the laws of, and located in, the United Kingdom, and some or all of its officers and directors may be residents of non-US jurisdictions. A US-based investor may not be able to sue a company located in the United Kingdom, or its officers or directors, in a foreign court for alleged violations of US securities laws, and it may be difficult to compel a foreign company and its affiliates to subject themselves to a US court's judgment.

Further details in relation to Overseas Shareholders are contained in the Scheme Document.

Forward-looking statements

This announcement may contain certain "forward-looking statements" with respect to OnTheMarket, CoStar UK and CoStar. These forward-looking statements can be identified by the fact that they do not relate only to historical or current facts. Forward-looking statements often use words such as "anticipate", "target", "expect", "estimate", "intend", "plan", "goal", "believe", "will", "may", "should", "would", "could" or other words or terms of similar meaning or the negative thereof. Forward-looking statements include, but are not limited to, statements relating to the following: (a) future capital expenditures, expenses, revenues, earnings, synergies, economic performance, indebtedness, financial condition, dividend policy, losses and future prospects; and (b) business and management strategies of CoStar, CoStar UK and/or OnTheMarket and the expansion and growth of OnTheMarket.

These forward-looking statements involve known and unknown risks, uncertainties and other factors which may cause actual results, performance or developments to differ materially from those expressed in or implied by such forward-looking statements. These forward-looking statements are based on numerous assumptions regarding present and future strategies and environments. None of CoStar, CoStar UK or OnTheMarket, nor any of their respective associates, directors, officers, employees or advisers, provides any representation, assurance or guarantee that the occurrence of the events expressed or implied in any forward-looking statements in this announcement will actually occur. You are cautioned not to place undue reliance on such forward-looking statements, which speak only as of the date hereof. All subsequent oral or written forward-looking statements attributable to CoStar, CoStar UK or OnTheMarket or any person acting on their behalf are expressly qualified in their entirety by the cautionary statements above. Should one or more of these risks or uncertainties materialise, or should underlying assumptions prove incorrect, actual results may vary materially from those described in this announcement. CoStar, CoStar UK and OnTheMarket assume no obligation to update publicly or revise forward-looking or other statements contained in this announcement, whether as a result of new information, future events or otherwise, except to the extent legally required.

No profit forecasts or estimates

No statement in this announcement is intended as a profit forecast or estimate for CoStar, CoStar UK or OnTheMarket in respect of any period and no statement in this announcement should be interpreted to mean that earnings or earnings per OnTheMarket Share for the current or future financial years would necessarily match or exceed the historical published earnings or earnings per OnTheMarket Share.

Publication on website

In accordance with Rule 26.1 of the Code, a copy of this announcement will be made available (subject to certain restrictions relating to persons resident in Restricted Jurisdictions), free of charge, on OnTheMarket's website at https://plc.onthemarket.com/recommended-cash-acquisition/ by no later than 12:00 noon on the Business Day following the date of this announcement. Neither the contents of this website nor the content of any other website accessible from hyperlinks on such website is incorporated into, or forms part of, this announcement.

Requesting hard copies

In accordance with Rule 30.3 of the Code, a person so entitled may request a hard copy of this announcement, free of charge, by contacting OnTheMarket's registrar, Link Group, on +44 (0) 371 664 0321 between 9.00 a.m. and 5.30 p.m. Monday to Friday (London time), excluding public holidays in England and Wales, or by submitting a request in writing to Link Group, Central Square, 29 Wellington Street, Leeds LS1 4DL or by e-mail to shareholderenquiries@linkgroup.co.uk. Calls are charged at the standard geographic rate and will vary by provider. Calls outside the United Kingdom will be charged at the applicable international rate. Different charges may apply to calls from mobile telephones and calls may be recorded and randomly monitored for security and training purposes. The helpline cannot provide advice on the merits of the Acquisition nor give any ?nancial, legal or tax advice. A hard copy of this announcement will not be sent unless so requested. In accordance with Rule 30.3 of the Code, a person so entitled may also request that all future documents, announcements and information to be sent to them in relation to the Acquisition should be in hard copy form.

Disclosure requirements of the Code

Under Rule 8.3(a) of the Code, any person who is interested in 1 per cent. or more of any class of relevant securities of an offeree company or of any securities exchange offeror (being any offeror other than an offeror in respect of which it has been announced that its offer is, or is likely to be, solely in cash) must make an Opening Position Disclosure following the commencement of the Offer Period and, if later, following the announcement in which any securities exchange offeror is first identified. An Opening Position Disclosure must contain details of the person's interests and short positions in, and rights to subscribe for, any relevant securities of each of: (a) the offeree company; and (b) any securities exchange offeror(s). An Opening Position Disclosure by a person to whom Rule 8.3(a) applies must be made by no later than 3.30 pm on the 10th Business Day (as defined in the Code) following the commencement of the Offer Period and, if appropriate, by no later than 3.30 pm on the 10th Business Day (as defined in the Code) following the announcement in which any securities exchange offeror is first identified. Relevant persons who deal in the relevant securities of the offeree company or of a securities exchange offeror prior to the deadline for making an Opening Position Disclosure must instead make a Dealing Disclosure.

Under Rule 8.3(b) of the Code, any person who is, or becomes, interested in 1 per cent. or more of any class of relevant securities of the offeree company or of any securities exchange offeror must make a Dealing Disclosure if the person deals in any relevant securities of the offeree company or of any securities exchange offeror. A Dealing Disclosure must contain details of the dealing concerned and of the person's interests and short positions in, and rights to subscribe for, any relevant securities of each of: (a) the offeree company; and (b) any securities exchange offeror, save to the extent that these details have previously been disclosed under Rule 8. A Dealing Disclosure by a person to whom Rule 8.3(b) applies must be made by no later than 3.30 pm on the Business Day (as defined in the Code) following the date of the relevant dealing.

If two or more persons act together pursuant to an agreement or understanding, whether formal or informal, to acquire or control an interest in relevant securities of an offeree company or a securities exchange offeror, they will be deemed to be a single person for the purpose of Rule 8.3.

Opening Position Disclosures must also be made by the offeree company and by any offeror, and Dealing Disclosures must also be made by the offeree company, by any offeror and by any persons acting in concert with any of them (see Rules 8.1, 8.2 and 8.4).

Details of the offeree and offeror companies in respect of whose relevant securities Opening Position Disclosures and Dealing Disclosures must be made can be found in the Disclosure Table on the Takeover Panel's website at www.thetakeoverpanel.org.uk, including details of the number of relevant securities in issue, when the Offer Period commenced and when any offeror was first identified. You should contact the Takeover Panel's Market Surveillance Unit on +44 (0) 20 7638 0129 if you are in any doubt as to whether you are required to make an Opening Position Disclosure or a Dealing Disclosure.