If you're wondering why you can't seem to get a raise – and maybe feeling frustrated and demoralized – it's worth looking at why your salary hasn't been raised. In many cases, understanding why your paycheck has stagnated can help you figure out the path to increasing it.

1. You haven't asked. A surprising number of people who are frustrated by their wages haven't actually asked for a raise. It's easy to feel like your employer should recognize the value of your work and compensate you accordingly – and certainly some employers will do that – but often you need to speak up and advocate for yourself. If you haven't asked your boss for a raise in over a year, now may be the time. Or, maybe you've asked for a raise but …

2. You haven't made a strong case that your work merits more money. Sometimes you can get a raise simply by saying something like, "Can we revisit my salary?" or "I was hoping we could take a look at my pay, since it's been a while since it was last adjusted." But you shouldn't assume that's all you'll need to say. In general, you should be prepared to lay out a compelling case about why your work is now worth more than it was the last time your salary was set – pointing to increased responsibilities and accomplishments.

3. It hasn't been long enough since your last salary increase. If you received a raise in the last 12 months, your boss isn't likely to give you one again so soon. There are some exceptions to this, like when your responsibilities change significantly or when you move to an entirely new role, but in general most companies won't give out raises more than once a year.

5. You're maxed out at the top of what you can make for this job at your company.There's usually a ceiling for how much it makes sense to pay for any given role, and if you stay in your job for a while, it's possible that you'll reach that ceiling. Sometimes this is based on internal company salary bands, and sometimes it's just a question of hitting the upper end of the market rate for the work you're doing.

6. Your boss doesn't realize what you're contributing. You could be doing outstanding work, but if your boss doesn't know about it, it probably won't be reflected in your pay. Make sure that you're sharing your accomplishments with your manager throughout the year – everything from praise from clients, problems you solved before they cost the company time or money, efficiencies you've implemented and any other victories you've racked up.

8. Your workplace has terrible compensation practices. In some companies, you can do everything right – perform at a high level, make your accomplishments visible, be easy and pleasant to work with – and still not see that reflected in what you're paid. Some companies do have compensation philosophies that center around paying people the lowest amounts they can get away with. Some companies won't increase salaries unless someone is on the verge of leaving for a higher-paying job (which is a terrible practice, since it drives good employees out the door). Some companies have unrealistic ideas of what it takes to hire and keep good workers. If you're working for a company with poor compensation practices, you might need to move on in order to get the raise you're looking for.