The line is also offering customers discounts of between £100 and £300 per person on selected holidays between 1 June and 25 March 2023 on bookings made before the end of May.
Eligible holidays can be secured with a 5% deposit and guests will also receive onboard spending money to be used against shore experiences, spa treatments or dining in the speciality restaurants.
P&O Cruises director of sales Ruth Venn said: "As part of our commitment to travel agents and to recognise the important role they play for P&O Cruises, we are delighted to reward them with a £50 bonus commission on each applicable booking.
"With fantastic springtime prices to promote to guests and increased commission, it’s a win-win for our travel agent partners."
The offer is applicable to the first two guests in a cabin only. The discount is not applicable to Saver prices, The World Cruise, Classic Southern Hemisphere Journeys and Exotic fly-cruises.
Eligible itineraries include a seven night Norwegian Fjords cruise on Iona from £749pp and 14-night Mediterranean fly-cruise on Azura from £1,599pp.