What "free" means here

Why it works that way

Nothing on an AWS bill is free in the sense of “not measured”. Free-tier usage is metered, priced, and then discounted to zero, which is why it still produces line items and why the free tier has usage type strings of its own. BoxUsage:freetier.micro is an EC2 instance-hour. Resource-Invocation-Count-FreeTier is a CloudFormation handler operation. AWS had to name the quantity before it could decline to charge for it.

That is not pedantry. A meter running at a rate of zero goes back to a non-zero rate the moment a condition outside the resource changes: a date passes, a monthly allowance fills, an account joins an organization, and the resource itself does not change at all.

The kinds of free

For fifteen years there were three: always free (a monthly allowance that never expires), 12 months free (from your sign-up date), and short-term trials (which start on first use, not on sign-up). On July 15, 2025 AWS rebuilt the front door and added a fourth mechanism: credits.

A new account now picks a plan at sign-up and gets USD $100 in credits either way, plus up to $100 more earned in $20 increments for five console activities. EC2, RDS, Lambda, Bedrock and Budgets. The credits expire twelve months from the account’s open date, on either plan.

• Free plan. You cannot incur a charge. It ends six months after account creation or when the credits are exhausted, whichever comes first, and then the account closes automatically, you lose access to your resources and data. AWS holds the content for 90 days; upgrade to a Paid plan inside that window or it is deleted permanently. Only Always Free offers are active: no short-term trials, no Savings Plans, no Reserved Instances. Joining AWS Organizations or standing up a Control Tower landing zone converts the account to a Paid plan and expires the credits immediately.
• Paid plan. All services, plus short-term trials. Credits are applied automatically to eligible usage; anything past them is charged at on-demand rates and the account stays open.

What went away is the 12-month tier. AWS now calls the old arrangement the Legacy Free Tier and says plainly that the 12-months-free offers “are only available to Legacy Free Tier AWS customers”. An account opened before July 15, 2025 keeps them for the remainder of its twelve months. Everyone else has always-free allowances, trials, and a credit balance with a clock on it. Even the eligible instance list forked on that date: before, “Free tier eligible” on EC2 meant t2.micro and t3.micro; on or after, it means t3.micro, t3.small, t4g.micro, t4g.small, c7i-flex.large and m7i-flex.large.

Boundaries from the inside out:

1. Always free allowance. Crossing it: $0.00 every month. Free. resets monthly, never rolls over, never expires
2. Short-term trial. Crossing it: $0.00 for a fixed window. Free. clock starts on first use, per service, often per Region: Paid plan only
3. Free Tier credits. Crossing it: $0.00 until the balance runs out. Free. $100 at sign-up plus up to $100 earned; expire 12 months after the account opens
4. Your invoice. Crossing it: on-demand rate. nothing left to absorb it: this is the rate card

The centre is free. Every ring you cross outward is a toll gate.

Whose free tier is it

Not your account’s. The Free Tier Terms state that an Organization “can only benefit from Offers from one account in the Organization”, and that AWS aggregates usage across all accounts in it to decide how much of an offer has been consumed. One free tier per consolidated billing family.

Order of application matters too, and AWS is explicit: “AWS applies AWS Free Tier benefits before Savings Plans benefits. Savings Plans cover excess usage that Free Tier doesn’t cover.” Free-tier hours leave the pool before a commitment gets a chance to match against them, a real reason a young organization’s Compute Savings Plan can look under-used in its first months.

What it costs

Free costs nothing. What costs something is the first hour on the other side of it. All rates below are us-east-1, on-demand, from the AWS Price List:

• t3.micro Linux: $0.0104 per hour, so the 750 hours a legacy account used to get free is about $7.80 a month.
• Public IPv4 address: $0.005 per hour, charged identically whether it is in use or idle.
• EBS gp3: $0.08 per GB-month; gp2 is $0.10; standard-tier snapshots are $0.05 per GB-month.
• Data transfer out to the internet: $0.09 per GB. The price list describes that tier, in its own words, as “first 10 TB / month data transfer out beyond the global free tier”.
• NAT Gateway: $0.045 per hour plus $0.045 per GB processed, with no free tier at all.

Path through Internet, Public IPv4, t3.micro, gp3 root volume, hop by hop:

• Public IPv4 (in use or idle) is billed on the Time meter for as long as it exists.
• t3.micro (metered, then discounted) is billed on the Time meter for as long as it exists.
• gp3 root volume (30 GiB) is billed on the Bytes meter for as long as it exists.

1. Internet to Public IPv4: inbound request. Not billed.
2. Public IPv4 to t3.micro: to the instance. Not billed.
3. t3.micro to gp3 root volume: baseline IOPS and throughput. Not billed.
4. t3.micro to Internet: response out. Billed on the Bytes meter, $0.09/GB.

Always-free allowances are monthly quantities that reset, and the Free Tier Terms are blunt about the unused part: “Unused usage amounts remaining at the end of the month under any Offers do not roll over to subsequent months.” The ones people actually meet: Lambda’s 1 million requests and 400,000 GB-seconds; Step Functions’ 4,000 state transitions, after which Standard workflows cost $0.025 per 1,000; DynamoDB’s first 25 GB of storage; CloudWatch’s 10 custom metrics and alarms, 1 million API requests, and 5 GB each of log ingestion and log archive.

Visibility is worse than the numbers suggest. AWS sends a Free Tier usage alert at 85 percent of a service’s limit, to the root user’s email address: on by default for standalone accounts, but off by default for an organization’s management account, the exact account that owns the only free tier in the family. The Billing console has a Free Tier page broken down by service, Region and usage type, with a GetFreeTierUsage API behind it. The EC2 console’s own free-tier box is explicitly not real time: AWS documents it as updating three times a day.

Traps

A free resource drags paid ones behind it. A free-tier EC2 instance is not a free-tier system. It needs a public IPv4 address to be reachable, and that address bills at $0.005 an hour whether attached or not. AWS added 750 hours a month of in-use public IPv4 to the EC2 free tier on February 1, 2024, but an idle Elastic IP was never covered, and only addresses you bring yourself under BYOIP are free outright. The root volume draws on a separate 30 GB allowance, snapshots on a separate 1 GB one, and a snapshot outlives the instance that made it. Move the instance to a private subnet to dodge the IPv4 charge and you have bought a NAT Gateway instead, which has no free tier and bills on two meters at once.

Some allowances are global and some are per-Region, and you cannot tell by looking. The Free Tier Terms say “we will aggregate your use across all AWS regions”, and the 100 GB of free monthly data transfer out is “aggregated across all AWS Services and Regions (except China and GovCloud)”. Trials count the other way. Amazon Detective grants “a 30-day free trial for each account in each Region”; Security Hub’s trial allowance is 10,000 ingested findings per account per Region per month. Turn a trial service on in six Regions and you have started six independent clocks that expire on six different dates.

A free service does not make its bytes free. Lambda’s allowance is always free, but the pricing page is clear that data “transferred ‘in’ to and ‘out’ of your AWS Lambda functions, from outside the region the function executed, will be charged at the Amazon EC2 data transfer rates”. Same-Region traffic to S3, DynamoDB, SQS, SNS, EFS, ECR and a handful of others is free; anything crossing the Region boundary is not, and it draws down the same shared 100 GB that every other service in your organization is drawing down.

One service can mean two different things by “free”. CloudFront’s pay-as-you-go model still carries the always-free 1 TB of monthly data transfer and 10 million requests. Its flat-rate plans, offered alongside it, have a Free tier at $0/month covering 1 million requests and 100 GB per distribution, and there the overage behaviour inverts: exceed a plan’s allowance and “you may experience reduced performance… but you won’t incur overage charges.” Same word, same service, allowances an order of magnitude apart, two different failure modes.

Nothing stops at the cliff, and the cliff’s shape depends on when you signed up. For a legacy account the twelve months end on a calendar date; the instance keeps running, the usage type does not change, and a rate that was zero is no longer zero. The 85 percent alerts track monthly allowances, not the end of the term, so they never fire for it. For a new-model account the failure is worse: on a Free plan, exhausting the credits or the six months closes the account and takes your access to the resources and data with it. On a Paid plan the credits absorb every overage silently until they are gone, so a dollar of overspend that used to arrive as a visible charge now just shortens the runway.