Why is my AWS bill so high?

AWS (Amazon Web Services) is brilliant at letting you start small and grow. It is less brilliant at telling you what you are paying for. Bills creep up month by month, and the breakdown is long and full of jargon.

The good news: the causes are nearly always the same handful of things. Here they are, roughly in the order I find them.

Prices below are AWS's own, in US dollars, for the London region (eu-west-2), as of October 2026. AWS bills in dollars.

1. Things left running that nobody uses

A test server from a project two years ago. A copy of the website someone made "just in case". A database for an app you stopped using. AWS charges for every hour they run, whether or not anyone uses them.

How to spot it: look through your servers (EC2 instances) and databases (RDS) and ask, for each one, "what is this for?" If nobody knows, that is a good sign.

2. Disks and backups nobody deleted

When a server is deleted, its disk often isn't. And backups of disks (snapshots) quietly pile up.

Disks cost about $0.116 per GB a month on the older gp2 type, whether attached to a server or not.
Snapshots cost about $0.053 per GB a month.
Deleting an old server image (an AMI) doesn't delete its snapshots. They carry on being charged.

What to do: delete disks that aren't attached to anything and snapshots you don't need, once you are sure.

3. Older disks that cost more than newer ones

AWS's newer gp3 disks cost about 20% less than the older gp2 type (about $0.093 against $0.116 per GB a month in London), and are usually as fast or faster. You can switch a disk over while the server keeps running.

4. Servers bigger than they need to be

Servers are often sized for a launch day that never came, or picked "to be safe". If a server's processor sits mostly idle, it is probably too big. AWS's own Compute Optimizer tool suggests better sizes for free.

Newer AWS servers built on their own Graviton processors are also about 20% cheaper than the equivalent Intel ones, if your software supports them (most modern web software does).

5. Network charges that are easy to miss

Public IP addresses: every public IPv4 address costs $0.005 an hour (about $3.65 a month), even if it isn't being used. They add up across lots of servers.
NAT gateways: a piece of network plumbing that lets private servers reach the internet. In London one costs about $0.05 an hour (around $36 a month) plus $0.05 for every GB that goes through it. Many small setups don't need one at all.
Data going out to the internet: the first 100 GB a month is free, then about $0.09 per GB.

6. Old database versions with a surcharge

If your database runs on AWS RDS and its version is past standard support, AWS automatically charges Extended Support on top. That includes MySQL 8.0 since August 2026 and PostgreSQL 13 since March 2026. It is charged per processor per hour and doubles in the third year. Upgrading the database version stops the charge.

7. Paying full price for steady servers

If a server runs all day, every day, and will for the next year, AWS Savings Plans can cut its cost by up to 66% in return for a one or three year commitment. Worth it for steady servers you are sure about. Not worth it for anything you might change soon.

Free tools to see what is going on

Cost Explorer: shows what you spend, by service, over time. Free in the AWS console.
AWS Budgets: sends you an email when spending goes over a figure you choose. Free to set up. Do this today, whatever else you do.
Compute Optimizer: suggests better server sizes. Free.

When to call someone

Some savings are quick and safe. Others, such as resizing servers, changing network setup or upgrading databases, can break things if done in a hurry. Call for help if:

You can't tell what each item on the bill is for.
The savings involve changing anything your website or app depends on.
You'd rather have a list of savings, with the risks spelled out, before anyone touches anything.

That is exactly what a hosting cost review gives you. And if the savings I find add up to less than my fee over a year, you don't pay it.