Exhibit 13.4

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Annual Report of RELX NV (the “Company”) on Form 20-F for the fiscal year ended December 31, 2016 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, N L Luff, Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ N L Luff

Chief Financial Officer

RELX NV

Dated: March 7, 2017