The process of landing the perfect apartment doesn’t end with signing your lease, paying your rent, and moving your belongings in. You also have to set up some or all of your utilities: electricity, gas, water, sewer, and TV/internet. When you create a new account with your utility companies, they may require a deposit upfront in addition to your monthly bills.

If all utilities are included or tacked on as a blanket fee in your monthly rent, your landlord may still require a utility deposit. This is less common than other types of deposits and fees you might find in a lease, but if you live in a multi-unit building with a single meter — or if your landlord keeps bills for all utility services in his or her name — it may apply to you.

As with security and pet deposits, utility deposits are meant to insure against losses — to your utility company or landlord — as a result of unpaid or underpaid bills. Here’s what you need to know.

Utility deposits are refundable

If you pay your bills in full, either to your service provider or your landlord, you should expect to receive your entire deposit back after a set number of payments or when your agreement ends. However, if you miss payments, or if your set monthly amount doesn’t actually cover your portion of your landlord’s utility cost, the deposit will be applied toward the discrepancy.

Deposits are (often) related to your credit

If you are setting up an account with a new utility service provider, the company will likely require you to demonstrate positive credit and a history of on-time payments. If your credit is good, your utility deposit may be reduced or waived. If your history is poor, you will still be able to set up your utilities — but you may have a higher deposit.

Utility deposit amounts vary widely

As stated above, you may pay no utility deposit at all. If a deposit is required, the amount could vary widely, as there are no strict regulations on what service providers and landlords can charge. For example, Duke Energy, which covers several states across the Southeast, says that the electricity deposit cost may range from $100 to $250 depending on the user’s projected monthly bill. Other utility companies require a blanket charge of $300 or more for residential electricity service agreements. If your cable or internet provider requires a deposit, it may also cover equipment usage.

Ask questions and get it in writing

As with all rental policies, learn your rights and be sure everything is documented in your service agreement, lease, or addenda. If your landlord is managing utility bills and participating in third-party billing — essentially dividing up total costs and then passing them on to tenants — make sure you understand how he or she is calculating what you owe. Keep track of all payments you make, and don’t be afraid to request proof of actual charges if you feel you are contributing too much.

Related: 10 questions you should always ask when apartment hunting