Complete Guide to Area Code 815: Everything You Should Know

Have you been receiving calls from the 815 area code, and don't know where the phone calls are coming from? Continue reading to learn about this phone number prefix that covers the Northern region of Illinois.

We’ll go over the history of the 815 area code, its time zone, how to report area code scams, how to get an 815 phone number, and how to figure out who is calling you using Intelius reverse phone lookup. 

815 area code overview: key facts

Fun Fact: Illinois is home to the only river in the world that flows backwards. 

What Area Code is 815?

815 area code location

The area code 815 serves the northern regions of Illinois, just outside of the Chicago metropolitan area. Notable counties include: Will, Winnebago, McHenry, and La Salle.

First established in 1946 by the North American Numbering Plan (NANP), 815 is one of the country's first 86 area codes, and served the entire region until the overlay 779 was introduced in 2007. 

These northernmost regions of Illinois are its most populous, with over 9 million residents. As a result, there aren’t that many vacant 815 phone numbers for individuals or businesses.

The majority of new numbers assigned in the area belong to the 779 overlay, which is still currently available. Illinois, especially Chicago, is home to a rich history of art, food, and architecture that makes it a popular tourist destination.  

Fun fact: Illinois was the first state to ratify the 13th Amendment to the Constitution, abolishing slavery, in 1865.

Cities in the 815 area code

• Chicago (western suburbs)
• Joliet
• Rockford
• DeKalb
• Crystal Lake
• Plainfield
• Woodstock

Well-known Communities in Illinois

• Chicago - The most populous city in Illinois, with around 2.7 million residents.
• Rockford - Home of the notable Anderson Japanese Gardens. 
• Joliet - The third most populous city in Illinois.
• Crystal Lake - A small town 45 miles northwest of Chicago.
• DeKalb - Named after Franconian-French war hero Joann de Kalb, who died during the American Revolutionary War.
• Rochelle - Known as the “Hub City”, located at the intersection of major transportation routes. 

Well-known Landmarks in Illinois

• Anderson Japanese Gardens
• Burpee Museum of Natural History
• Gaylord Building 
• Rock Cut State Park
• Klehm Arboretum & Botanic Garden

Zip codes serviced by area code 815

There are approximately 636 total zip codes represented by the 815 area code. Below are some of the most popular zip codes within the area code 815. 

• 60608 – Chicago
• 60431 – Joliet
• 61101 – Rockford
• 60012 – Antioch
• 60515 – Sandwich
• 60140 – DeKalb

Neighboring Area Codes

Area Code 815: Time Zone & Business Tips

If you’re reaching out to someone or a business in the 815 area code and you’re located in another time zone, like California (PT/Pacific Time), it’s important to know the corresponding business hours for the Central Time Zone (CT).

For example, if you’re in California and trying to make a call to an 815 area code, remember that PT is two hours behind CT. It would be best to call during 9 AM-2 PM PDT, which corresponds to 11 AM-4 PM CDT.

• Standard time: CDT, UTC−5:00 hours
• Daylight saving time: +1:00 during the second Sunday of March, Central Daylight Time (CDT, UTC−5) / -1:00 during the first Sunday of November
• Time zone abbreviation: CT (Central Time) / CDT (Central Daylight Time)

Fun Fact: The first McDonald's was built in Des Plaines, IL!

The history of area code 815 (Northern Illinois) 

Beginning in 1947, during the creation of the North American Numbering Plan, the first 86 area codes were assigned across North America.

The introduction of an easy-to-understand number system for telecommunications across the entire United States, Canada, and the Caribbean changed communications standards for the entire continent. 

Illinois was first assigned the 815 area code, but as the state’s population increased rapidly over the remainder of the century, there were few new numbers available. In response, authorities introduced the 779 overlay code in early 2007, to ease some of the strain on available numbers for new residents and customers. 

The 779 area code will continue to have available numbers and won’t require a new code addition until at least 2039 (PDF, page 192).

Overlays

Illinois is served by more than a handful of area codes and overlays. 

With over 2.7 million residents, the number of reservations can fill up quickly. To keep up with demand, there are 18 different area codes overall, but only two that serve the northern region of Illinois, the 815 and its overlay, 779.

Why a 815 number still turns heads

While the 779 overlay has more numbers available, the 815 code is still sought after and viewed by many as Illinois’ original number.

Many businesses, longtime residents, and longstanding institutions still have their original 815 numbers, making them more recognizable and iconic than the newer 779 overlay numbers. 

How to Get an 815 Phone Number

If you’re wondering how to get an 815 area code, there are a number of ways you can get your own. 

1. Request an 815 number reservation via a landline or a mobile carrier. Examples include Verizon®, AT&T®, or T-Mobile®, however, these numbers are becoming increasingly rare. 
2. Use a randomly generated number from a VoIP service like Google® Fi, Grasshopper, or RingCentral.

Shop for a number using a phone number marketplace, such as Numberbarn.

Spotting and Blocking 815 Scams

Illinois residents receive tens of thousands of scam calls and robocall attempts. Make sure to stay vigilant, use Intelius reverse phone lookup, and understand your phone’s built-in blocking features to avoid becoming the victim of a scam.

In 2024, the FTC’s National Do Not Call Registry report listed 102,969 total complaints from the state of Illinois. Of those complaints, there were about 811 per 100,000 residents.  

• Rank: 4
• Complaints: 102,969
• Robocalls: 55,820
• Live scam calls: 33,989

Red Flags to Watch Out For

There are three top scam types in Illinois, but scammers generally target these three categories: financial, medical, and impersonation. 

1. Debt Consolidation Scams

• Bad actors who attempt to pose as trusted financial organizations, banks, credit unions, collection agencies, and credit card companies.
• Nearly 80% of all calls on this topic are robocalls.
• These scams make up 8,609 of all 102,969 complaints.

2. Medical & Prescription Plans

• These are scams that target individuals with health complications or who are otherwise involved with medical institutions. These can include hospitals, health insurance, and other public institutions. 
• About 50% of all scams in this category are carried out by robocallers.
• These scams make up 7,528 of all 102,969 total complaints.

3. Imposter Scams

• Scams revolving around impostors either use human impersonators or AI/robot-generated representations. These scams aim to take the trusted identities of friends and family, targeting call recipients for financial information or sensitive personal data. 
• About 65% percent of all scams in this category originate from robocallers.
• These scams make up 7,503 of all the 102,969 total complaints.

Illinois recorded 1,581 complaints per 100,000 residents and ranks number four in the country. While Illinois has a relatively high report rate, the highest rank for most scam calls in-state actually belongs to Delaware.

How to Block 815 Area Code Phone Calls

Take note if you are receiving random calls from area codes that you don’t recognize. These numbers may be trying to scam you by pretending to be reputable companies, like banks, tech companies, social media, and even your phone carrier. 

1. Use your smartphone’s phone app to set up call blocking

• iPhone: Navigate to the Recents list, inside your iOS phone app. Select the ⓘ icon next to the number, and then select Block this Caller.

Android: Navigate to the Phone app. Once you see the list of recent phone numbers, tap the number in question, select Details, and then select Block. 

2. Use a third-party app to filter out spam calls

• If you subscribe to a phone call spam app, you can get powerful tools to protect your peace of mind and prevent unwanted ringing from scam phone calls. It's worth noting that some of these services, like Truecaller or Hiya, offer free protection so you don’t have to pay for a premium solution if you don’t want to. 

3. Add your phone number to the National Do Not Call Registry 

• If you’re looking for maximum impact with minimal effort, you can file a complaint with the Federal Trade Commission. When you make reports to the FTC, it helps the rest of the country’s phone users track and shut down scam call centers located in Illinois and other U.S. states. 

How to Look up an 815 Phone Number

Using search engines: Use a search engine, like Google, to enter the phone number and see if it gets matched with previously indexed businesses.

Check the official FCC scam number database: Use this official government resource by the Federal Communications Commission to track, identify, and report scam numbers. It is a tried and trusted tool for combating scam calls. 

Running a reverse phone lookup: Use a reverse phone search to reveal names, addresses, and more associated with a specific 815 area code number. 

Need more intel on an 815 area code? Run a reverse number search and find the information you’re looking for. 

Frequently Asked Questions About Area Code 815