FIRST SUPPLEMENTAL INDENTURE

Exhibit 4.2

FIRST SUPPLEMENTAL INDENTURE

This FIRST SUPPLEMENTAL INDENTURE (this “Supplemental Indenture”) is executed as of December 15, 2015 among Expedia, Inc., a Delaware corporation (the “Company”), the Subsidiary Guarantors party hereto, HomeAway Software, Inc., a Delaware corporation and a subsidiary of the Company, HomeAway.com, Inc., a Delaware corporation and a subsidiary of the Company, and BedandBreakfast.com, Inc., a Colorado corporation and a subsidiary of the Company (each, an “Additional Guarantor”), and The Bank of New York Mellon Trust Company, N.A., a national banking association, as Trustee (the “Trustee”) under the Indenture dated as of December 8, 2015 (the “Indenture”).

WITNESSETH

WHEREAS, the Company and the Subsidiary Guarantors party thereto have entered into the Indenture with the Trustee pursuant to which the Trustee acts as trustee for the holders of the Company’s 5.000% Senior Notes due 2026;

WHEREAS, pursuant to Section 10.7 of the Indenture, the Company agreed to cause any Domestic Subsidiary that becomes a guarantor or borrower under the Credit Agreement to become a Subsidiary Guarantor by executing a supplemental indenture;

WHEREAS, each Additional Guarantor is agreeing to become a guarantor under the Credit Agreement;

WHEREAS, the Indenture permits the Company, the Trustee and each Additional Guarantor to execute a supplemental indenture for the purpose of adding a Subsidiary Guarantor; and

WHEREAS, all acts and requirements necessary to make this Supplemental Indenture the legal, valid and binding obligation of the Company, the Subsidiary Guarantors and each Additional Guarantor have been done.

AGREEMENT

NOW, THEREFORE, in consideration of the agreements set forth herein and for other good and valuable consideration, the sufficiency of which is hereby acknowledged, the parties hereto agree as follows:

Section 1. DEFINITIONS. All capitalized terms used in this Supplemental Indenture not defined herein shall have the same meanings ascribed to them in the Indenture.

Section 2. ADDITIONAL GUARANTORS. Each Additional Guarantor by the execution of this Supplemental Indenture agrees to be a Subsidiary Guarantor under the Indenture and to be bound by the terms of the Indenture applicable to Subsidiary Guarantors.

Section 3. EFFECTIVENESS. This Supplemental Indenture shall become effective upon execution by all parties hereto.

Section 4. ACKNOWLEDGMENT AND CONSENT. Each of the Subsidiary Guarantors party hereto acknowledges that its consent to this Supplemental Indenture is not required, but each of such Subsidiary Guarantors nevertheless does hereby agree and consent to this Supplemental Indenture.

Section 5. GOVERNING LAW. This Supplemental Indenture shall be governed by, and construed in accordance with, the laws of the State of New York.

Section 6. MISCELLANEOUS. This Supplemental Indenture may be executed in various counterparts which together will constitute one and the same document. This Supplemental Indenture is an amendment supplemental to the Indenture and this Supplemental Indenture will henceforth be read together with the Indenture.

Section 7. TRUSTEE. The Trustee makes no representations as to the validity or sufficiency of this Supplemental Indenture. The recitals and statements herein are deemed to be those of the Company and the Subsidiary Guarantors and not of the Trustee.

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IN WITNESS WHEREOF, the parties hereto have duly executed this Supplemental Indenture as of the day and year first above written.

[Signature Page to 2026 Supplemental Indenture]

[Signature Page to 2026 Supplemental Indenture]

[Signature Page to 2026 Supplemental Indenture]

[Signature Page to 2026 Supplemental Indenture]

[Signature Page to 2026 Supplemental Indenture]

[Signature Page to 2026 Supplemental Indenture]

[Signature Page to 2026 Supplemental Indenture]

[Signature Page to 2026 Supplemental Indenture]