463 Area Code: Indianapolis and Central Indiana — The 317 Overlay

Introduction

The 463 area code is a full overlay on 317, covering Indianapolis and most of central Indiana — the state's capital city and largest metro, home to Eli Lilly and Company, the world's third-largest pharmaceutical company by market cap, and the Indianapolis Motor Speedway, the single largest spectator sporting venue on Earth. Salesforce's tallest tower outside San Francisco anchors the downtown skyline, and the healthcare and life sciences cluster that has grown around Lilly makes Indianapolis one of the most pharmaceutical-dense mid-sized cities in the country.

This guide covers the 463 footprint, Indianapolis's pharmaceutical, technology, and motorsports anchors, Eastern Time calling hours, the 2015 overlay history, and how to provision a 463 number with STIR/SHAKEN attestation from day one.

Where the 463 area code reaches

• Marion County — Indianapolis city proper, including the Mile Square downtown, Meridian-Kessler, Broad Ripple, Fountain Square, and the airport corridor
• Hamilton County — Carmel, Fishers, Noblesville, and Westfield — the fast-growing northern suburbs and home to a major biotech and software cluster
• Boone County — Zionsville and Lebanon, the affluent northwestern suburbs
• Hendricks County — Avon, Brownsburg, and Plainfield — the western suburbs and Indianapolis Airport logistics corridor
• Johnson County — Greenwood, Franklin, and the southern suburban communities
• Shelby County — Shelbyville and the eastern agricultural communities
• Morgan County — Martinsville and the communities southwest of Indianapolis

Because 463 is a full overlay on 317, 10-digit dialing is mandatory throughout the footprint — including calls between two 317 numbers or two 463 numbers on the same exchange.

Indianapolis International Airport, in the Hendricks County corridor, is home to the second-largest FedEx Express hub in the world after Memphis — a 2.4-million-square-foot sorting facility that opened in 1988 and now processes up to 99,000 packages an hour. That cargo operation makes the western suburbs one of the most logistics-dense parts of the entire 463 footprint, adding a third major industry alongside pharmaceuticals and motorsports.

Hamilton County has its own claim to fame beyond biotech: Carmel has built more than 160 roundabouts since the late 1990s, replacing nearly every signalized intersection in the city and earning it the title of "roundabout capital of the United States." Carmel alone accounts for roughly 2% of every roundabout in the country, and the redesign has become a case study in traffic engineering circles for the crash reductions it delivered — a small but telling example of how deliberately central Indiana's fastest-growing suburbs have been planned. More detail sits on our letsdial page.

Indianapolis: Eli Lilly, Salesforce, and the racing capital

Eli Lilly and the pharmaceutical anchor

Eli Lilly and Company, founded in Indianapolis in 1876, remains headquartered on the south side of downtown — the city's largest private employer and one of the top ten pharmaceutical companies globally by revenue. Lilly's insulin, Prozac, and Trulicity franchises, combined with recent oncology and immunology investments, have made Indianapolis the informal capital of US pharmaceutical manufacturing. The company's presence has seeded a dense biotech and CRO (contract research organization) ecosystem across Hamilton County and the I-465 ring.

Salesforce Tower and the technology sector

Salesforce Tower Indianapolis, at 49 stories the tallest building in Indiana, is the physical symbol of the city's technology ambitions. Salesforce's significant Indianapolis presence (the company acquired ExactTarget, which was headquartered here, in 2013 for $2.5 billion) brought thousands of software engineering, marketing cloud, and enterprise sales roles to the 463 market. The acquisition catalyzed a broader tech startup ecosystem centered on the Mass Ave and Bottleworks District corridors.

Indianapolis Motor Speedway and motorsports economy

The Indianapolis Motor Speedway, located in Speedway (Marion County), seats more than 250,000 spectators — the largest single-day sporting event venue in the world. The Indy 500, held every Memorial Day weekend, is the world's largest single-day sporting event by attendance. The motorsports economy extends beyond race day: Indianapolis is home to dozens of IndyCar and NASCAR race teams, technical suppliers, and engineering firms, making it a legitimate motorsports engineering hub alongside its pharmaceutical identity.

Professional sports beyond racing

Indianapolis's sports economy extends well past the Speedway. Lucas Oil Stadium, a 62,000-seat retractable-roof stadium downtown, has hosted the Indianapolis Colts since 2008 and has drawn major events including a Super Bowl and multiple NCAA Final Fours. Gainbridge Fieldhouse, in the heart of downtown, is home to both the NBA's Indiana Pacers and the WNBA's Indiana Fever, giving the 463 footprint four professional sports franchises within a few blocks of each other — a downtown sports and entertainment density that few mid-sized metros can match, and one that drives significant hospitality and event-related call volume throughout the year.

The NCAA itself relocated its national headquarters from Kansas City to downtown Indianapolis in 1999, and the NCAA Hall of Champions on West Washington Street now anchors the city's identity as a college-sports administrative hub alongside its professional teams. Monument Circle, the literal center of downtown Indianapolis, is dominated by the 284-foot Soldiers' and Sailors' Monument, dedicated in 1902 and still the city's most recognizable landmark — the traffic circle around it was long home to Anthem, now Elevance Health, one of the largest health insurers in the country and still headquartered in Indianapolis after moving its offices to Virginia Avenue in 2018. More detail sits on our letsdial page.

Healthcare and life sciences in the 463 footprint

Beyond Eli Lilly, Indianapolis hosts Indiana University Health (IU Health) — the state's largest hospital system — Ascension St. Vincent, Franciscan Health, and the Richard L. Roudebush VA Medical Center. The Indiana Biosciences Research Institute and the Central Indiana Corporate Partnership have invested hundreds of millions in life sciences infrastructure, and Roche Diagnostics has its North American headquarters in Carmel (Hamilton County). The combination creates an unusually talent-dense healthcare and life sciences labor market for a city of Indianapolis's size.

Indianapolis also has a legitimate claim to being a birthplace of the modern electronic health record. The Regenstrief Institute, founded in 1969, built one of the country's first electronic medical record systems in 1972 for what is now Eskenazi Health, and later developed the Indiana Network for Patient Care — one of the oldest and largest health information exchanges in the country, now linking billions of data points across hospitals and providers statewide. That informatics legacy has made Indianapolis a genuine hub for health-tech and clinical research talent, not just pharmaceutical manufacturing.

Time zone and calling hours for 463

Indianapolis and most of central Indiana observe Eastern Time year-round — UTC-5 in winter (EST) and UTC-4 during Daylight Saving (EDT). Indiana was famously one of the last states to adopt Daylight Saving Time statewide, which it did in 2006. Indianapolis shares the clock with New York, Philadelphia, and Washington DC. West Coast callers are three hours behind — plan outbound campaigns before 2 p.m. Pacific to reach the full Indianapolis business day.

463 history: overlay on 317 in 2015

Indianapolis has carried the 317 area code since the NANP's original 1947 assignments — one of the original codes that has served Indiana's capital without a geographic split. As central Indiana's population and wireless density grew through the 2000s, the 317 pool depleted steadily. The Indiana Utility Regulatory Commission approved 463 as a full overlay on the 317 footprint, activating it in 2015 and implementing mandatory 10-digit dialing. Both codes carry equal local recognition in the Indianapolis market.

How to get a 463 number

1. 1Cloud phone platform — search available 463 numbers and activate an Indianapolis line the same day. letsdial provisions a central Indiana number in under three minutes on a free trial, no credit card required.
2. 2Port your existing 317 or 463 number — already on another carrier? Port it in at no charge with no call downtime during the transition.
3. 3Wireless or landline carrier — valid for a physical device but slower to provision and harder to scale without per-seat hardware.

> [TIP] Note: letsdial applies STIR/SHAKEN A-level attestation automatically on every 463 number and handles 10DLC registration for text campaigns — your Indianapolis number is verified from the first call.

463 is officially documented under the North American Numbering Plan, which governs area code assignments across the US, Canada, and the Caribbean. That record is published in full as North American Numbering Plan.

Conclusion

The 463 area code overlays 317 across Indianapolis and central Indiana — Eli Lilly's global pharmaceutical headquarters, Salesforce Tower, the Indianapolis Motor Speedway, IU Health, and the Hamilton County biotech corridor. A local 463 number gives businesses immediate credibility in a mid-sized market with outsized pharmaceutical, technology, and healthcare employment density.

Letsdial provisions 463 numbers in under three minutes — STIR/SHAKEN attestation and 10DLC text registration included, no credit card required. Search available Indianapolis-area numbers today.

Frequently Asked Questions