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Posted by nprateem 16 hours ago

AWS: Inaccurate Estimated Billing Data – $1.7 billion

URL already posted: https://health.aws.amazon.com/health/status

I've got an estimated bill for $1.7 BILLION over this month. Normal usage is < $5.

Obvs have created an urgent AWS support ticket. Anyone else seeing something like this?

Update: Reddit link: https://www.reddit.com/r/aws/comments/1uyuaw7/help_my_bill_s...

1037 points | 638 commentspage 5
dirkk0 14 hours ago|
same here, I am still in shock. took me 10 minutes to find the 'operational issue' message in the dashboard. longest 10 minutes of my life.
charles_f 14 hours ago||
Can you not set spending limits in AWS?
inigyou 14 hours ago|||
No you can't. Spending limits imply realtime billing backend flows and they also imply deleting all your data so that you don't pay for storage.
benterix 12 hours ago|||
I heard this false justification already in 2007, in spite of many customers asking for it.

Incidentaly, smaller competitors solved this issue decades ago, while the big cloud decided it is more convenient never to implement it.

inigyou 10 hours ago||
Big cloud didn't want to rewrite its billing systems from scratch to please its smallest customers.
bcrosby95 9 hours ago||
With AI it should take like a weekend.
inigyou 4 hours ago||
I think they already tried rewriting billing with AI. Very smartly they only tried rewriting the estimator first. This post is about the outcome of it.
handoflixue 13 hours ago||||
Realtime billing seems entirely within the abilities of AWS.

"Limits except for Storage" seems even easier - I don't think I've ever heard of a storage-based billing story, although I'm sure one or two exist

everforward 11 hours ago|||
Storage-based billing is huge, unless you mean something other than “places that make you pay for storage separately”.

Also many places I’ve worked, storage is a huge part of the spend but that depends a lot on what you do. e-commerce doesn’t use a ton of it, but if you handle user-generated content or do any kind of training (LLM, computer vision, etc) then you can very much end up in a place where storage becomes a top line number for infra spend.

GitHub pre-Copilot was probably like that. They host a shitload of data, most of which is just at rest the majority of the time. Storage and networking are probably the majority of their infra costs.

inigyou 10 hours ago||
Storage-based billing stories. When an account is hijacked it's always for compute, not storage.
everforward 9 hours ago||
Oh, I also don’t think I’ve ever seen that but I’m not surprised. Even if you could steal a huge amount of storage, filling it with data would take ages and the cat and mouse game of moving the data as hacks get uncovered would be untenable.

I have seen things get hacked for bandwidth, back in the days before you could rent a gbps uplink from the cloud for $0.12. Some scene release groups would hack into universities or companies to do the initial seeding over their super fast links. It used storage, but that wasn’t really the goal.

Planktonne 11 hours ago||||
They could do it; they don't want to.
minitoar 11 hours ago|||
What is a storage-based billing story?
kgwgk 11 hours ago||
Once upon a time in a cloud kingdom far, far away a big, beautiful bill was issued based on storage causing much disconcertion. Etc.
SAI_Peregrinus 10 hours ago||||
> and they also imply deleting all your data so that you don't pay for storage.

Not necessarily. They could imply that your storage becomes inaccessible immediately, but only gets deleted after some time period (say, 1 month). What spending limits do depends on the implementation.

inigyou 10 hours ago||
That's even more work to implement. And now you store files on a second account that pays for only one day a month to not get deleted.
0cf8612b2e1e 5 hours ago||
No wiggle room to come up with a workable solution. Let’s go shopping instead.
prmoustache 11 hours ago|||
Storage could switch to read only.

That would mean an outage but that is still better than going bankrupt and teach you a thing or two about monitoring.

boristsr 14 hours ago||||
No, alerts but not limits.
perching_aix 10 hours ago||||
Not only can you not set limits, even the alarms are not real time. So it is entirely possible to get on the hook for terrifying amounts of money and not know until it's all too late.
reformd 14 hours ago|||
he did, 140 billion :D
masafej536 14 hours ago||
If you owe AWS 140B dollars its their problem ;)
lelandfe 10 hours ago||
This just hit global news: https://www.theguardian.com/technology/2026/jul/17/amazon-we...

> Amazon Web Services customers receive bills for up to $1.5tn after global glitch

euio757 10 hours ago||
> One UK man whose bill is usually less than £1 says he ‘almost had a heart attack’ when he saw £5.8bn invoice

That sucks, some people will get legit panic attacks and worse over this, especially for the smaller, more believable numbers in the 50k-500k range.

Hope they recover and sue for medical bill costs, emotional damage etc.

And like one reddit user suggests, everyone affected should write to their representative about hard billing caps protections

dabinat 5 hours ago||
It says a lot about AWS that people believed these estimates were real. Amazon does not have good safeguards to prevent astronomical bills.

If someone gets access to your account they can just buy a 3-year reserved instance u7in-24tb.224xlarge and it will add almost $2m to your bill.

dlev_pika 9 hours ago||
1.5 trillion? Those are rookie numbers.

How about $5,544,640,717,404.09?

That was in my inbox this morning lmao

dv_dt 15 hours ago||
Cynically I wonder if this has an outcome as an unintentional (or intentional) anchoring exercise for future cost increases
ardacinar 12 hours ago|
I hope they're not planning for that large of a cost increase.
graemep 12 hours ago||
Someone I know woke up this morning to over 3 trillion dollars.

Love to see how hyperscalers make your life easier and less worrying.

fnoef 9 hours ago||
That’s the smoking gun. Should have used gigabytes instead of bytes. Thank you for pointing me at the issue.
fuorilegge 15 hours ago||
I have just received a similar alert for $ 5b

AWS on their support data is reporting this:

Inaccurate Estimated Billing Data

Jul 17 3:03 AM PDT We continue to work to resolve the issue affecting estimated cost and usage data displayed in the Billing and Cost Management Console. We have identified the root cause as an issue with unit pricing within the estimated billing computation subsystem and we are working on a mitigation. The displayed billing estimates do not reflect actual usage and charges. There are no customer actions required at this time. Once the issue has been mitigated, we expect full resolution to take multiple hours as we work through recomputing the estimated billing data. We will provide another update by 4:00 AM PDT or sooner if more information becomes available.

Jul 17 2:07 AM PDT Beginning on July 16 7:38 PM PDT, we began displaying incorrect estimated billing data in the Billing and Cost Management Console. Our engineering teams are engaged and investigating root cause. We will provide another update by 3:00 AM PDT or sooner if more information becomes available.

Jul 17 1:33 AM PDT We are investigating issues with Cost Explorer reflecting inaccurate estimated billing data.

iamrik9 15 hours ago||
I feel much better after seeing the $B estimates here; I only have an estimate of $34M so far

Folks can track it directly on AWS Health: https://health.aws.amazon.com/health/status

bfjvibybd6cuvu6 11 hours ago||
It's ok, I owe them 1.22 trillion.
consp 11 hours ago|||
Maybe you went over 9,223,372,036,854,775,807 twice and came back to positive.
paulddraper 12 hours ago||
Peanuts
simonreiff 10 hours ago||
Question: Why does AWS need to roll back estimated bills to a "last known good" state? I get wanting to do that for ACTUAL billing mistakes, but for estimates, they're just that -- approximations. I guess it's fine for predictive purposes to store estimates so they can be compared to actual usage and optimized. But why would AWS bind the values of present estimates to the estimates made earlier in the month. The calculation should always be:

1. Current month's usage * applicable rates; + 2. Estimated future usage for the month * applicable rates.

And Item 1 obviously requires proper data persistence, but Item 2 is just a projection. If they don't have Item 1 correct, AWS's whole system is in question, but I don't think that's the issue. I'm going to guess now -- looking forward to reading the root cause analysis -- that the problem is that someone decided to get too fancy with the estimates, and built a latent requirement that all prior estimates for the month must be available to compute the current estimate. Without estimates working, no estimates are available, and some denominator in an averaging or smoothing or normalizing function goes to 0; then everyone's estimated bill explodes without bound (subject to floating-point arithmetic) resulting in trillion-dollar estimates.

donavanm 9 hours ago|
Thats not really how estimates work. The actual metering data is ingested in near real time. The metering * pricing plan is processed within a few hours; thats what youre seeing for “estimated spend” IIRC. The actual billing accumulation is done later, at the end of the cycle, because pricing has cross service discounts, price tranches, credits tied to total spend, etc.

“Rolling back” estimated bills is reprocessing the historic metering data by an older or newer pricing plan version. As i mentioned in another comment someone will have messed up a metering type vale (eg GB/B). Thats why theyll need a few hours to redrive the metering data.

nottorp 14 hours ago||
Looks like they set up a LLM to estimate billing?
craigmoliver 12 hours ago|
Ditto on the heart attack. My cost estimate for the month is currently $223,509,270,216.17. My girlfriend suggested contacting Elon for help. Glad I found this thread. Maybe I should create new keys anyway, this stuff freaks me out.
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