UK nationals made up the largest number of PPSN allocations last year, according to new figures from the Central Statistics Office.
A total of 102,850 foreign nationals were allocated a PPSN in 2017.
The United Kingdom had the highest number of PPSN allocations (15,346) in 2017, and has continued to account for the highest number of allocations by country since 2009.
Romania recorded the second highest number of allocations (12,081), followed by Brazil (10,361), Poland (6,817), Spain (6,339), Italy (5,998) and India (5,782).
The CSO said a total of 447,416 foreign nationals who were assigned PPSNs in the fifteen years up to and including 2017 recorded some employment during 2017.
Accommodation and food service activities, Wholesale and retail trade; repair of motor vehicles and motorcycles, Administrative and support service activities, and Manufacturing and Information and communication sectors accounted for 63.0% (281,941) of all foreign national employment activity in 2017.
Of the 102,850 given a PPS number last year, 45,374 had no PAYE employment or any engagement with the social welfare system in 2017.
The figures come from an annual analysis of records of the Revenue Commissioners, the Department of Employment Affairs and Social Protection, and the CSO.