UniSource bill pay basics
UniSource Energy Services is the utility that serves parts of Arizona, including Tucson and surrounding areas. You can pay your bill online through their website, by phone, by mail, or in person at payment centers. The method you choose depends on how quickly you need the payment to post and whether you want to set up automatic payments.
UniSource does not charge a fee for most payment methods, but some third-party payment processors may add a small charge if you use their service. Before you pay, check your bill to see the due date — paying after that date may result in a late fee, even if the payment is in transit.
Key Takeaways
- You can pay UniSource bills online at their website, by phone at 1-877-786-5833, or by mailing a check to the address on your bill.
- Online payments typically post within one to two business days; mail payments take longer depending on postal delivery time.
- Setting up automatic payments from your bank account removes the risk of missing a due date and requires only a few minutes of setup.
- Late fees begin accruing the day after the due date shown on your bill, so confirm the exact date before you pay.
Paying online through UniSource's website
Go to unisource.com and look for the "Pay My Bill" or "Make a Payment" link on the homepage. You will need your account number, which appears on your bill, and a valid payment method — a bank account for electronic transfer or a debit or credit card. Enter the amount you want to pay and confirm the payment date.
Online payments made before 5 p.m. Arizona time on a business day usually post the next business day. If you pay after 5 p.m. or on a weekend, the payment may not post until the following business day. UniSource's website will show you a confirmation number immediately after you submit the payment; save this for your records.
If you do not have internet access or prefer not to enter payment information online, you can call UniSource directly at 1-877-786-5833 to pay by phone using the same account number and payment method.
Mailing a check or money order
Write your account number on the check or money order and mail it to the address printed on your bill. UniSource's mailing address changes depending on which part of Arizona you live in, so always use the address on your current bill rather than looking up a general address online.
Mail payments typically take five to ten business days to arrive and post, depending on postal delivery in your area. If your due date is fewer than ten days away, mailing a check is risky — the payment may not arrive in time to avoid a late fee. For bills due soon, use online payment or phone payment instead.
Include the payment stub from your bill if possible, as it helps UniSource match the payment to your account quickly. If you do not have the stub, write your account number clearly on the check itself.
Setting up automatic payments
Automatic payments remove the need to remember due dates and reduce the chance of late fees. Log into your UniSource account online, go to the billing or payment section, and select "Set Up Auto Pay" or "Automatic Payments." You will need to provide your bank account information and choose a payment date — most people choose the due date shown on their bill, or a few days before it.
Once automatic payments are active, UniSource will withdraw the amount due from your bank account on the date you selected each month. You can change the payment date or pause automatic payments at any time through your online account. If your bill amount varies significantly from month to month, you can set the automatic payment to cover only a fixed amount and pay the difference manually, or you can adjust the automatic amount each month.
What to do if you cannot pay on time
If you know you cannot pay by the due date, contact UniSource before the due date passes. Call 1-877-786-5833 and ask about payment arrangements or hardship programs. UniSource may be able to extend your due date or set up a payment plan that spreads the amount owed over several months.
Late fees begin the day after the due date, so calling before that date is important. If you have already missed a payment, paying as soon as you can will stop additional late fees from accruing, though the fee for the missed payment itself will remain on your account.
Understanding your bill and account number
Your UniSource bill shows your account number at the top or in a highlighted box — this is the number you need for any payment method. The bill also shows the due date in bold or in a separate section. Some bills show a "past due" amount if you have missed a previous payment; this amount must be paid along with the current bill to bring your account current.
If you cannot find your account number on a paper bill, log into your online account at unisource.com or call 1-877-786-5833 and ask for it. Having this number ready before you attempt to pay saves time and reduces the chance of the payment being applied to the wrong account.
Payment timing and posting
The date you make a payment and the date it posts to your account are often different. Online and phone payments post within one to two business days. Mail payments take longer because they must travel through the postal system and then be processed by UniSource's payment center.
UniSource considers a payment on time if it is received by the due date, not if it is posted by the due date. This means a check mailed on the due date may not arrive until after the due date, and you could be charged a late fee even though you sent the payment on time. For this reason, mail payments should be sent at least one week before the due date.
Frequently Asked Questions
Can I pay my UniSource bill with a credit card?
Yes, you can pay with a debit or credit card through UniSource's website or by phone. Some third-party payment processors may charge a convenience fee if you use a credit card, so check the payment screen before confirming. Paying with a bank account transfer typically has no fee.
What happens if I pay after the due date?
A late fee will be added to your account. The amount varies, but it is typically a percentage of your bill or a flat fee. Late fees begin accruing the day after the due date shown on your bill. Paying as soon as you realize you are late will stop additional fees from being added, though the initial late fee will remain.
How do I know if my payment went through?
Online and phone payments show a confirmation number immediately after you submit them. Write down this number for your records. You can also log into your UniSource account online to see your payment history and the status of recent payments. Mail payments may take longer to show up in your account history.
Can I change my automatic payment date?
Yes. Log into your UniSource account online, go to the automatic payments section, and select the option to edit or change your payment date. Changes usually take effect within one to two billing cycles. If you need to pause automatic payments temporarily, you can do that through the same section.
What if I overpay my bill?
If you pay more than the amount due, the extra amount becomes a credit on your account. UniSource will apply this credit to your next bill, or you can request a refund by calling 1-877-786-5833. Credits typically remain on your account indefinitely until they are used or refunded.