Maybe you’ve been at your company for a couple of years. Five years. Ten years. And in all that time you’ve never asked for a raise. You might think that gives you more of a right to ask for one now, but you’d be wrong.
How long you’ve been at a company doesn’t necessarily translate into success. And that alone certainly doesn’t entitle you to additional compensation. But the main reason you should avoid saying this is because it’s a trap. When you point out how long you’ve been there and couple it with the fact you’ve never gotten a raise, all you’re doing is putting it in your boss’ head that you haven’t done anything raise-worthy in years, or else you already would’ve been recognized. That might not be the case in real life, but keep in mind your boss' perception can unfortunately become your reality.
If you really have done the work to earn a raise, focus on that and highlight your greatest achievements instead of implying that your boss is a miser who hasn’t paid you fairly in years.