You are picking between Comcast Business and AT&T Business. Both will quote you a monthly rate. Both quotes will look close. And both are missing the numbers that actually decide which one costs less.
The real answer lives in three places. The fees. The contract term. And what happens at renewal.
The quoted price is the smallest part
Comcast usually wins the first quote. On a 500 Mbps cable plan, the monthly rate often lands under what AT&T asks for the same speed. So people sign with Comcast and feel good about it.
Then the bill shows up.
Comcast adds a Broadcast TV Surcharge and other line items that are not taxes . These fees are straight Comcast revenue. They do not appear on the quote. They appear on the bill. On a typical account they add $15 to $30 a month, and they climb every year.
AT&T runs a cleaner bill on fiber. Fewer junk fees. The tradeoff is a higher starting rate. So the gap you saw on the quote starts to close the moment real fees hit.
Cable versus fiber changes the math
This is the part most buyers skip. Comcast sells you cable. AT&T sells you fiber where it is lit.
Cable gives you fast downloads and slow uploads. Fiber gives you the same speed both ways. For a team on video calls all day, or one that sends big files, the upload speed is what matters. That is when AT&T fiber starts to pencil out even at a higher rate.
If your building only has Comcast, this whole debate is moot. Check what is lit at your address first. Everything else follows from that.
The three year total
Here is where the split shows up. Comcast tends to write a good year one rate, then step the price up. AT&T tends to hold a flatter rate across the term but starts higher.
Run a real example. A firm we reviewed in Atlanta had a 500 Mbps Comcast plan. Quoted rate looked fine. Over the full term, fee creep and a year two step pushed the true cost well past the number on paper. We got them down 27% by renegotiating at the 90 day mark .
AT&T accounts usually need less mid term surgery, but the entry price means you pay more up front. Over three years the two carriers often land within a few dollars of each other. The winner depends on your fees, your term length, and whether you actually negotiate.
The renewal trap hits both of them
Carriers write contracts so the renewal catches you off guard . The window to negotiate is about 90 days before the end date. Miss it and you roll into another year at the same rate, or a higher one.
This is true for Comcast. It is true for AT&T. Put the end date in your calendar the day you sign. Most people do not, and both carriers count on that.
So which one costs less
There is no clean winner. There is only your address, your usage, and your willingness to negotiate.
Pick Comcast if the fiber is not lit at your building and your uploads do not matter much. Watch the fees. Fight the ones that are not taxes.
Pick AT&T if your team lives on uploads and you want fewer surprise line items. Expect to pay more up front.
Either way, the price you sign is not the price you keep. That part is up to you.
The fastest way to know which carrier is cheaper for your address is to stop guessing. Get both quotes. Then check them against what your market is actually paying this month. See what that looks like on our example report.