International Civil Aviation Organisation recommendations, adopted last week, are that pilots, subject to medicals, can fly in either seat of heavy jets up to the age of 65, but the other pilot must be under 60.
This is a guideline, and many countries have more restrictive legislation. The USA, for example, does not allow any captain or co-pilot of any Part 121 public transport aircraft to be over the age 60.
In Europe (including the UK), Joint Aviation Requirements do not allow captains of heavy jets to fly after they turn 60, but they may continue in the right-hand seat until age 65. However, pilots may fly smaller types such as regional aircraft as captains until 65, but in all cases, if one pilot is above 60, the other must be younger than 60.
Like the USA, the Czech Republic, France, Italy and Portugal adopt more restrictive rules that allow co-pilots to be over 60, but not captains, and impose the rule on foreign aircraft that transit their airspace.
The British Airline Pilots’ Association has called for this “nonsense” legislation to be relaxed, arguing pilots are subject to stringent medical and technical tests, which establish their competence and fitness to fly.

Source: Flight International