GPW Benchmark SA, the administrator of reference interest rate indices, announced on September 30, 2025, its decision to discontinue the calculation of WIBID® and WIBOR® Reference Rates for the following Fixing Terms on the dates specified below:

• Overnight (O/N) – as of October 1, 2026,
• Tomorrow/Next (T/N) – as of December 22, 2025,
• 2 Weeks (2W) – as of December 22, 2025,
• 1 Year (1Y): 
  • as of December 22, 2025, based on the current methodology,
  • as of December 22, 2026, in connection with the obligation imposed on the administrator by the supervisory authority to continue publishing the reference index under Article 21 of the Benchmark Regulation¹, following a change in the methodology for calculating the WIBOR® reference rate for the 1Y Fixing Term.

The discontinuation as of October 1, 2026, for the O/N Fixing Term and as of December 22, 2025, for the T/N and 2W Fixing Terms indicates the dates on which the reference index value for the respective Fixing Term will no longer be determined. For the 1Y Fixing Term, as of December 22, 2025, WIBID® will no longer be published for this Fixing Term, and WIBOR® will be determined for the first time using an algorithmic method intended to be applied until December 21, 2026.

On October 31, 2025, GPW Benchmark SA announced, based on the results of public consultations, that during the period of the obligation to calculate the WIBOR® index for the 1Y Fixing Term imposed on the administrator by the Polish Financial Supervision Authority for 12 months, i.e., from December 22, 2025, to December 21, 2026, the value of WIBOR® for the 1Y Fixing Term will be determined using an algorithmic method based on the value of WIBOR® for the 3M Fixing Term, adjusted by a correction spread determined according to the publicly consulted dynamic spread correction method, with a correction coefficient of 0.57 (5-year calibration period).

It was also indicated that the 1-week Fixing Term (SW) remains a point on the money market curve but will be calculated as an index within the meaning of the Benchmark Regulation to ensure informational transparency. The index values calculated for the SW Fixing Term cannot be used in contracts and financial instruments.

The above actions do not concern WIBOR® and WIBID® reference indices for the 1M, 3M, and 6M Fixing Terms, which are the most commonly used reference indices by lenders and borrowers who have included a variable interest rate clause in their contracts.

According to the communication of the Polish Financial Supervision Authority dated  September 30, 2025, all supervised entities, especially lenders and borrowers, are expected to immediately refrain from entering into new contracts (including financial contracts) or issuing financial instruments that would use the WIBOR® reference rate for the ON, TN, SW, 2W, or 1Y Fixing Terms. The Commission also indicates that immediate refraining from entering into new contracts using the WIBOR® reference rate for the ON, TN, SW, 2W, or 1Y Fixing Terms is also in the legal interest of parties to non-financial contracts, including entities not supervised by the Polish Financial Supervision Authority². 

The decision to discontinue the calculation of WIBID® and WIBOR® Reference Rates for certain Fixing Terms was made under Article 21 of the Benchmark Regulation, taking into account the overall results of the review of WIBID® and WIBOR® Reference Rates, the conclusions and recommendations of the Polish Financial Supervision Authority provided to the administrator in connection with the assessment of the WIBOR® reference index’s ability to measure the relevant market or economic realities, and in response to the Polish Financial Supervision Authority’s communication on the results of this assessment³. The decision to discontinue certain Fixing Terms aligns with the actions outlined in the Roadmap of the National Working Group for benchmark reform⁴ adopted by its Steering Committee, and at the same time aligns the shape of the Polish money market curve with the structure of some foreign, current and historical, money market curves. The decision thus supports the implementation of the Roadmap for the process of replacing WIBOR® and WIBID® reference indices for those Fixing Terms where, as in the case of the T/N and 1Y Fixing Terms, Transaction Levels are relatively low and the scope of application is limited, and where discontinuation supports the introduction of a new reference interest rate index.

More information on the discontinuation of WIBID® and WIBOR® Reference Rates for selected Fixing Terms is available on the Administrator’s website: GPW Benchmark – News

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¹Regulation (EU) 2016/1011 of the European Parliament and of the Council of 8 June 2016 on indices used as benchmarks in financial instruments and financial contracts or to measure the performance of investment funds and amending Directives 2008/48/EC and 2014/17/EU and Regulation (EU) No 596/2014 (OJ EU L 2016 No. 171, p. 1, as amended)
²https://www.knf.gov.pl/komunikacja/komunikaty?articleId=95290&p_id=18
³https://www.knf.gov.pl/?articleId=93868&p_id=18
⁴https://www.knf.gov.pl/dla_rynku/Wskazniki_referencyjne?articleId=93431&p_id=18