Renters know that filling out a rental application is an essential part of the process. The application allows you to express interest in a property while also providing the landlord or property manager with the bits of information they need to determine if you're qualified to rent the unit.

But certain blemishes on your record or past transgressions could hurt your chances of being able to score your ideal apartment or house, and cause the landlord to reject your application. To help you stay ahead of the curve and in the know, take a look at some of the most common—and unexpected—reasons your rental application can be denied.

1. Inadequate or unverified income

The most common reason rental applications get rejected is because of a person's income. Typically, property managers want you to be making at least three times your monthly rent to ensure you can afford it; landlords in big cities may require that your annual income be at least 40 times the monthly rent—sometimes even more. For example, if you're looking at renting a place for $3,000 a month, you would need to make at least $120,000 per year.

But you'll have to show evidence—in the form of pay stubs, employer's letters, or direct deposits—to prove you will be able to make rent. If you can't show proof of income, your application may be rejected.

2. Poor credit

Not paying your bills on time or having significant debt can lower your credit score and make you an undesirable renter. Many properties have a minimum credit score that renters must have if they want to rent a home there.

3. Bad references

Your rental application will likely have a section where you need to list a few references: a past landlord, employer, or any unbiased person who can speak to how responsible and trustworthy you are.

If your property manager calls a few references and discovers that you were constantly late paying rent, or turned your place into a meth lab, your application will very likely be denied.

4. Incorrect income

Most property managers and landlords want you to list your gross income (the total amount before anything is deducted) on the application, but some people mistakenly put their net income (what they're left with after taxes and other deductions like health insurance). That’s a very common mistake that a lot of people make. Doing this can disqualify you from being able to rent the property, so when filling out your application be sure to ask about this.

5. Evictions

Obvious but worth noting: Having prior evictions on your record can make it more difficult for you to rent an apartment. If you failed to pay rent and were evicted, landlords might assume you are not a reliable renter.

6. Unexplained gaps in your rental history

Gaps in your rental history might trigger a rejection. Why? For one, the property management company or landlord may suspect that you vacated your last property before the lease was up, which is a big, waving red flag.

But a gap doesn't mean you'll be automatically rejected. If there was a legitimate reason for the gap—you moved in with your family, took time off to travel, etc.—be sure to explain that upfront.

7. Unpaid balance from your last property management company

Even if you paid your last month’s rent on time, having an unpaid balance left over from your last property management company can cause a rejection. Some companies allow tenants to pay for their utilities through them. For instance, you may have an unpaid water bill from the last place you rented from.

If your property management company reached out to you and you didn’t get the message, it may send the bill to a collections agency. If you owe money to a collections agency, that will usually cause your application to be turned down flat.

The simple way to prevent this mix-up is to make sure your landlord has your correct contact information before you move.

8. Too many people applying to live in one house

States have their own laws on how many people can live in a house, so if you're applying to rent a one-bedroom apartment with a large family, that could be a roadblock.

For example, most judges will rule that only two people can live in one-bedroom unit. It’s not a hard and fast rule, but in my experience as a landlord and attorney, it’s sort of the benchmark.

If you’re trying to rent a space and you want more people in the space than allowed, you need to be able to demonstrate to the landlord or property managers why the space would work for your living situation. For instance, if the bedrooms are fairly spacious, it could show that more than two people could comfortably live there.