Here’s a tricky question. Some bosses are enlightened enough to recognize that you can ask every day so long as you can demonstrate that your value has increased substantially since yesterday. Others get shirty if you ask more than once every three or even five years. You’re going to have to take your own boss’s view into account on this – a combination of intelligent guesswork, observing what pay awards others get and even
How much is too much?
nonchalant questioning should establish the answer.
There’s no reason why you shouldn’t ask your boss directly, but if they realize why you’re asking the likelihood is they’ll put a longer time span on it than they would actually accept in reality. Once they’ve told you directly that they wouldn’t want to give a pay rise more often than once every two years, you’ve made it much harder (although not impossible) to ask them for another rise in a year’s time.
Once you’ve established your boss’s view as closely as you can, aim to ask for a rise as often as you can, making sure you can really justify it each time. If you can only ask once every two or three years, I’d wait a few months until you’ve improved your value substantially and then ask for a really good rise – it’s going to have to last you a while.