Area codes · +1
Area code 815
Area code 815 is centred on Rockford, Illinois. We hold 5,718 allocated blocks for it across 200 rate centres, split 35% mobile, 51% landline and 14% VoIP.
The other area codes laid over 815
Area code 815 does not have Rockford to itself. 1 other code — 779 — serves the same rate centres, laid over the same ground rather than dividing it. That is an overlay: a new code added when the old one ran out of numbers, covering the same streets. Two neighbours can hold different area codes, so the code says roughly when a number was issued rather than where it sits.
7792,970 blocks, 139 rate centres, mostly mobile
Each holds its own blocks and its own carrier mix, so a 815 number and a 779 number from the same street can report different line types. Filtering Rockford by area code needs all 2 of them.
815 is not confined to Rockford itself: its blocks sit across 200 rate centres, named in the table below.
Illinois is split across 17 area codes — 224, 618, 708, 815, 217, 309 and others. By allocated blocks 815 is the 4th largest of them, holding 9% of the Illinois total.
Where 815 numbers are concentrated
NANPA truncates rate-centre names to ten characters and drops the spaces, which is why Crystal Lk is shortened. Names are reproduced as recorded rather than expanded — the abbreviation is the key the block data is filed under.
| Rate centre | Blocks | Share of 815 |
|---|---|---|
| Rockford | 546 | 10% |
| Joliet | 382 | 7% |
| Kankakee | 180 | 3% |
| De Kalb | 174 | 3% |
| Woodstock | 167 | 3% |
| Lockport | 156 | 3% |
| Freeport | 137 | 2% |
| Sterling | 116 | 2% |
| Mchenry | 113 | 2% |
| Crystal Lk | 104 | 2% |
| Plainfield | 95 | 2% |
| Morris | 90 | 2% |
| Ottawa | 84 | 1% |
| La Salle | 78 | 1% |
| Minooka | 75 | 1% |
| Momence | 66 | 1% |
| Oglesby | 59 | 1% |
| Princeton | 58 | 1% |
| New Lenox | 55 | 1% |
| Belvidere | 54 | 1% |
| Manhattan | 51 | 1% |
| Coal City | 48 | 1% |
| Streator | 47 | 1% |
| Frankfort | 46 | 1% |
176 further rate centres in 815 hold fewer blocks than these.
Carriers holding the most 815 blocks
Onvoy583 blocks
Illinois Bell540 blocks
Frontier North, Inc.435 blocks
T-Mobile Usa, Inc.348 blocks
T-Mobile USA, Inc.339 blocks
Verizon Wireless301 blocks
No carrier holds more than 10% of 815; the blocks are spread thin across many companies.
These are original allocations. A number keeps its digits and its block when its subscriber moves network, so a ported 815 number still reports the carrier it started with. Closing that gap needs a live query against the routing database. How line type is derived.
Check a single 815 number, or run a whole list through the free cleaner — neither uploads anything.
Common questions
Where is area code 815?
Area code 815 covers Rockford, Illinois. It is not the only code there: 779 is an overlay on the same rate centres, so a Rockford, Illinois number can start with any of them.
Is a 815 number a mobile or a landline?
It can be either, and the digits do not say which. North American mobile and landline numbers share the same ranges, so the answer comes from the carrier holding the block. In 815 the split runs 35% mobile, 51% landline and 14% VoIP, so landline is the most likely single answer.
Which carriers hold 815 numbers?
The largest holders are Onvoy, Illinois Bell, Frontier North, Inc.. That is the carrier the block was allocated to, which is not necessarily the network a given number sits on today.
How many 815 numbers are there?
The code holds 5,718 allocated blocks in our copy of the numbering plan. A block is 1,000 or 10,000 consecutive numbers depending on how deeply it has been pooled, so 815 covers on the order of 5,718,000 possible numbers — most of which have never been issued to anyone.