Because a security deposit can be between 100 and 200 percent of your monthly rent, of course you want to get it back when you move out.

Landlords should understand how to manage security deposits before they sign the lease, and renters should read up on strategies for getting their security deposits back when they move out.

California has laws that address the landlord’s responsibility to return this deposit, and while other states may not spell them out as clearly, most states do address security deposits in landord-tenant state laws.

Most state laws mandate that a landlord must either return the security deposit within 15 to 30 days of the renter moving out. Many states also require landlords to supply itemized lists of expenses to account for any withheld funds as well.

Reasons for keeping all or part of the deposit

Whether the law requires a written list or not, a landlord can keep all or part of the deposit to compensate for unpaid rent, cover the cost of cleaning the unit, make repairs, and replace damaged or lost furniture or personal property.

Here are eight reasons you might lose all or part of your security deposit:

1. The rental wasn’t clean

You don’t have to leave a rental unit in pristine condition when you move out. But when excessive cleaning is required, the landlord may apply part of your deposit to cover the expense of cleaning it properly.

Cleanliness can bring up an exploration of the word “reasonable.” For example, it’s reasonable for the landlord to clean the kitchen and bathroom when a tenant moves out, but they may consider it unreasonable to spend time removing stains that could have been prevented. If the cleaning job calls for extra effort, the money will come from your security deposit.

2. You didn’t give enough notice

When a renter decides to move out, they need to give the proper amount of notice, typically 30 or 60 days, in writing. If you failed to do that, the landlord can apply the security deposit as reimbursement for the rent you were obligated to pay.

Note: This doesn’t apply if the conditions that caused you to vacate the premises render the unit uninhabitable, and the landlord is unable—or refuses—to correct them.

3. Overused utilities racked up costs

When the landlord pays utilities, it’s easy to forget about them and accrue excessive charges. Again, the word “reasonable” is important, because the landlord may consider you keeping the thermostat at 85 degrees, raising the electric bill $100 a month, unreasonable. You could be docked for the extra charges when you move out unless you’ve worked out an agreement.

4. You left stuff behind

When you move out, your stuff has to go with you. If you leave it for the landlord to throw away, the disposal costs will come out of your security deposit.

5. Existing damages weren’t documented

When you rent a car, you wouldn’t think about driving off the lot without first checking for damage. The same should be true when moving into a rental unit. Take photos and videos with your phone to record any damages or wear and tear before you move in.

Comparing this record—along with a written checklist—at move out can protect you from liability for damage you didn’t cause, which can save you from having to pay for it.

6. You made repairs without permission

You didn’t like the generic colors of the walls, so you repainted without asking your landlord first. The landlord is entitled to deduct the cost of restoring the original paint colors from your security deposit.

The same is true for any unauthorized change or repair you might have made, no matter how much of an improvement you believe it is. Next time you want to make repairs or improvements, check with your landlord first, and only proceed when you get approval in writing.

7. You didn’t read the lease

The biggest mistake a renter can make is to sign a lease without reading it. That’s like buying a house without inspecting it. You might be happy that you’re moving into your dream apartment, but take the time to read the lease.

Don’t be pressured into signing before reading. Take the lease home, and spend some time reading it, so you know what conditions you have to meet to make your stay a happy one. And knowing these details will help you get your security deposit back when you move out.

8. You misunderstood the lease terms

Ordinary wear and tear” and “reasonable effort” are just two of the vaguely worded phrases you might find in your lease. It’s up to you to clarify these phrases before you sign.

If your interpretation differs from that of the landlord, the time to talk about it is when you’re moving in, not when you’re moving out. Take this opportunity to open the lines of communication. It’s a great way to start a relationship with your new landlord!