Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of endo-1,4-β-xylanase produced by Komagataella phaffii ATCC PTA-127053 (Xygest™ HT) as a zootechnical feed additive for poultry. The production strain is genetically modified. No viable cells nor recombinant DNA of the production strain were detected in the final product. Therefore, the Panel concluded that the additive does not pose any safety concern regarding the production strain. The FEEDAP Panel concluded that Xygest™ HT is considered safe for chickens for fattening at 30,000 U/kg and in laying hens at 45,000 U/kg, with a wide margin of safety. These conclusions can be extended to chickens reared for laying/breeding and extrapolated to all poultry species for fattening and reared for laying/breeding and to ornamental birds. The conclusions on laying hens are extrapolated to all laying poultry species. The use of Xygest™ HT in animal nutrition is of no concern for consumer safety and this feed additive is considered safe for the environment. The Panel also concluded that Xygest™ HT is not irritant to the eyes and skin but should be considered a dermal and a respiratory sensitiser. The Panel concluded that the additive Xygest™ HT has a potential to be efficacious for laying hens under the proposed conditions of use and this conclusion can also be extrapolated to all laying poultry species. The Panel could not conclude on the efficacy of the product for chickens for fattening due to insufficient data.