Charleston is a Tier C metro that behaves like a Tier B on the peninsula and a Tier C everywhere else. Downtown blocks near Broad and Meeting have multiple on-net fiber providers within the same building, which means downtown pricing is closer to Atlanta than to Augusta. Cross the Ashley or the Cooper and the picture changes fast. West Ashley, Mount Pleasant, Daniel Island, and Summerville have pockets of fiber and large gaps of cable-only or fixed-wireless-only service. The other thing buyers miss: Home Telecom and IQ Fiber will quote aggressively against Spectrum and AT&T in the suburbs, but you have to ask.
Charleston is mostly a Spectrum and AT&T market. Spectrum Business has the dominant cable footprint across the metro. AT&T Business Fiber covers a growing share of commercial blocks downtown. Home Telecom serves parts of the Lowcountry suburbs with fiber. T-Mobile fixed wireless is widely available.
The pricing problem in Charleston is the assumption that the local fiber co-ops are not worth quoting. Home Telecom often comes in 20 to 30 percent below the incumbent on fiber to the building in the suburbs.
How Charleston's market is shaped
Charleston's commercial activity sits in three places. The Central Business District holds the legal, financial, and government corridor downtown. The King Street Commercial Corridor runs through dense small-business and mid-size office tenancy on the peninsula. Avondale, on the West Ashley side, is the suburban office and retail spine outside the urban core. The Medical University of South Carolina and Boeing South Carolina are two of the largest commercial accounts in the metro and shape what enterprise pricing looks like for the rest of the market.
In February 2025, IQ Fiber announced a 10 gig-capable fiber deployment in the Charleston metro, with first phases targeting West Ashley and Mount Pleasant. That puts a real fiber overbuilder against Spectrum and AT&T in this market for the first time in years. One pricing wrinkle: properties inside the King Street Business Improvement District pay a special fee on top of normal property taxes under South Carolina's Municipal Improvements Act, which can show up indirectly in commercial lease pass-throughs.
What you should be paying
These are dedicated internet ranges from current carrier wholesale data, marked up to typical retail.
Charleston dedicated internet, typical retail (mid 50%)
Monthly recurring charge, dedicated internet access (DIA). Numbers are derived from current carrier wholesale quotes. Shown as a metro-tier band where city-level data is thin.
| Speed | Typical retail (mid 50%) | Sample size |
|---|---|---|
| 100 Mbps | $630 – $1,060/mo | n = 6 |
| 500 Mbps | $955 – $1,660/mo | n = 6 |
| 1 Gbps | $1,195 – $2,000/mo | n = 7 |
| 10 Gbps | $1,560 – $6,250/mo | n = 6 |
If your bill sits above the high end of the band, you are likely overpaying.
Analyze My Bill FreeFor AT&T Business Fiber at 1 Gbps, expect $150 to $230 a month for a single office. For Spectrum coax at 600 Mbps, the fair price is $150 to $230 a month.
Carriers worth quoting in Charleston
Five carriers cover most addresses in the metro.
- Spectrum Business. Coax everywhere, fiber in select buildings.
- AT&T Business Fiber. Strong commercial fiber footprint downtown.
- Home Telecom. Fiber across parts of the Lowcountry suburbs.
- T-Mobile Business Internet. $85 a month for 200 to 300 Mbps. Useful benchmark.
- Verizon 5G Business Internet. $99 a month at 400 Mbps.
If you have not had three of these on a quote sheet, you have not run a real comparison.
What to do this week
- Pull your most recent invoice. Find the contract end date and the side fees.
- Get one quote outside Spectrum. T-Mobile Business Internet is the fastest benchmark.
- Compare your base rate to the bands above. If you are 20 percent above the high end, the retention call is worth making.
See where your Charleston bill sits against current rates
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Carriers worth a quote here
- Spectrum Business
Dominant cable footprint across the entire tri-county area, from downtown to Summerville to North Charleston. Their coax product is the default for most small offices, but they will hold list pricing unless you bring a written competing quote.
- AT&T Business
Strong fiber presence downtown along Meeting, King, and East Bay, plus the Medical District around MUSC. Coverage thins out quickly in West Ashley and James Island. On-net buildings get the best pricing; off-net quotes come back high because of local loop costs.
- Comcast Business
Limited footprint compared to Spectrum, mostly in parts of North Charleston and the industrial corridor near the airport. Worth a quote if you are near I-526, otherwise not in play for most peninsula addresses.
- Lumen Business
Long-haul and enterprise fiber serving larger accounts, including some of the Boeing and port-adjacent industrial buildings. Not a real option for a single-office SMB, but relevant for multi-site customers with a Charleston node.
- Crown Castle Fiber
Metro fiber rings through downtown and along the medical corridor. On-net in select commercial buildings on the peninsula. Useful as a third quote when you want to pressure Spectrum and AT&T.
- T-Mobile Business
5G fixed wireless is widely available across the metro and is the cheapest backup option for a small office. Real-world throughput varies block to block, especially near the peninsula's older masonry buildings.
What internet costs in Charleston, South Carolina right now
Charleston, South Carolina market notes
Common questions about business internet in Charleston, South Carolina
Is AT&T Business Fiber available at my Charleston address?
Downtown peninsula and parts of the medical district are well covered. West Ashley, James Island, and Mount Pleasant have spotty coverage that varies block to block. The only reliable way to know is a serviceability check at your exact street address, not your zip code. If AT&T comes back off-net, the quote will include a local loop charge that pushes the MRC well above the on-net rate.
What should I pay for 1 Gbps dedicated internet in Charleston?
Expect $1,195 to $2,000 a month at retail for true DIA with an SLA. Downtown on-net fiber buildings come in at the low end. Off-net suburban addresses, single-tenant buildings, and short contract terms push you toward the top. If you are paying over $2,000 for a 1 Gbps DIA in Charleston and your contract is more than two years old, you are overpaying.
Is Home Telecom or IQ Fiber worth quoting?
Yes. Home Telecom serves parts of the Lowcountry suburbs with fiber and often prices 20 to 30 percent under Spectrum and AT&T for comparable speeds. IQ Fiber's 2025 buildout in West Ashley and Mount Pleasant gives you a third quote in zip codes that used to be a two-carrier market. Always ask. Carriers will not volunteer that a smaller competitor is on-net at your address.
Why is my Spectrum Business bill higher than my neighbor's?
Three usual reasons. You signed during a different pricing window, your modem rental and Wi-Fi line items add up to $15 to $25 a month, or your contract auto-renewed at the old rate while new customers got promotional pricing. Pull the bill, identify every line item, and ask Spectrum retention for current-customer renewal pricing. If they will not move, get a written AT&T quote and try again.
Should I use T-Mobile 5G as a primary connection for my Charleston office?
As primary, only if you are a small office with no real uptime requirement and your block has tested signal. It is the right product as a backup behind a Spectrum or AT&T primary, where it can keep credit card terminals and email running during an outage. Charleston's older masonry construction downtown can knock signal down a tier inside the building.
How long does fiber install actually take in downtown Charleston?
On-net buildings: 14 to 30 days. Off-net peninsula addresses inside the historic district: 60 to 120 days is realistic because of right-of-way permitting and facade review. If a carrier rep promises 30 days on an off-net downtown build, ask for that in writing with a missed-install credit. The credit clause is what tells you whether they actually believe their own timeline.