How to limit bandwidth usage in WHM

Bandwidth is the amount of data a site transfers in a month. A bandwidth limit in WHM is how a server admin or reseller stops one account from eating the transfer allowance of a whole machine. Updated for 2026 against the current cPanel & WHM documentation, this text tutorial covers four things. Where the limits live. How to watch usage. Which server-wide switches turn the whole thing on and off. And what actually happens to a site that goes over its cap.

Two places to set a limit

A bandwidth limit can come from the package an account uses. It can also come from an override on the individual account. Packages are the sane default. You set the allowance once, give it to every account on that plan, and change it in one place. Overrides exist for the customer who needs a temporary exception. Menu labels differ a little between WHM versions. So treat the paths below as a map, not as a transcript.

Set the limit in a package

Go to WHM > Home > Packages > Add a Package. In the Resources section you will find Monthly Bandwidth Limit (MB), next to the disk quota. The value is in megabytes, so 500 GB is entered as 512000. Package names cannot be changed later, which is why cPanel says not to put prices or sizes in them. You edit an existing package in Edit a Package, and accounts pick up the new value.

Override a single account

For one-off changes, open WHM > Home > Account Functions > Limit Bandwidth Usage. Select the account. WHM then shows its IP address, owner, contact addresses, start date, theme, package and disk usage. Click Limit, enter the new allowance, and click Change. The same field appears as Monthly Bandwidth Limit (MB) in WHM’s Modify an Account interface, if you are already editing other settings there.

One practical detail from the documentation: the system checks bandwidth limits once per day, between midnight and 6:00 a.m. So a limit you raise at noon may not take effect until that run. Lifting a cap is not always an instant fix for a site that is already restricted.

Monitor what accounts are actually using

Go to WHM > Home > Account Information > View Bandwidth Usage. It lists every account with User, Domain, Xfer (the transfer used so far), Limit and Usage as a percentage. Links at the top move between months. A toggle switches the display between best-fit units and megabytes. An edit icon next to a row changes that account’s limit without leaving the page. You can also filter the list down to one reseller’s accounts.

Two measurement quirks are worth knowing. First, the main domain’s figure includes traffic from its alias (parked) domains. An alias is a second domain name that serves the same site. Second, WHM counts HTTP, FTP, SMTP and POP3/IMAP traffic. That is why its totals will not match AWStats, Webalizer or any analytics script, because those only see browser requests.

The server-wide switches in Tweak Settings

WHM > Home > Server Configuration > Tweak Settings holds the settings that decide whether limits mean anything at all. On the Notifications tab:

• Bandwidth limit check. On by default. It restricts HTTP service on its own for accounts that go over their limit. Turn it off and the server stops all bandwidth notifications. It then treats every account as if it had unlimited transfer, and the per-account numbers become decorative.
• Send bandwidth limit notification emails. Also on by default. It turns on the family of percent warnings below it.
• Bandwidth usage warning toggles at 70, 75, 80, 85, 90, 95, 97, 98 and 99 percent. Out of the box, the 80 percent warning is the one that is on. Turning on 90 and 95 as well gives a customer a realistic chance to react before the cap bites.

The Packages tab carries a separate default. It is the bandwidth limit put on new packages when the person who makes them cannot set unlimited bandwidth. Set it to something you are comfortable handing out automatically.

What happens when an account goes over

A bandwidth limit is not the same as a suspended account, and cPanel’s own documentation is emphatic about the difference. When an account goes over its monthly allowance, the system restricts services reached over HTTP and HTTPS only. FTP, mail and DAV keep working. So the customer can still collect email and upload files while their website returns an error to visitors. Nothing is deleted, and no password is locked.

The restriction clears on its own. The first time the server processes bandwidth statistics in the new month, the account is no longer over its limit, and normal service resumes. Do you need to restore a site sooner? Raise the account’s limit, and remember the once-a-day check window. Moving the account to a package with more headroom works too.

A workable policy for resellers

1. Set package limits with real margin. A cap that is hit every month brings you support tickets, not revenue.
2. Turn on the 80 and 90 percent warnings, so customers hear from the server before they hear from their visitors.
3. Check View Bandwidth Usage once a month. Look for accounts whose usage curve is bending upward. Those are upgrade talks, not enforcement problems.
4. Remember that mail counts. An account with heavy mailing lists can hit a transfer cap with almost no web traffic.
5. Document the policy in your terms, including what happens at the limit, so nobody is surprised by a site that stops serving pages.

Hosting tip

Are you hitting bandwidth ceilings on a reseller plan? The fix is usually a platform with transfer measured in terabytes rather than gigabytes. You also want root access to the WHM settings above, which lets you change anything on the server. Compare allowances and included transfer in our VPS hosting and dedicated server sections. Then check how the provider handles an overage: a hard stop, a throttle, or a per-gigabyte charge. The answer to that question matters more than the headline number.