Is there a possibility that an EC2 instance ID may duplicate an ID with another account?

Question

Hello.

Is there a possibility that an EC2 instance ID may duplicate an ID with another account?  
I ask because the following documentation seems to be unique at the region level, but does not mention duplication at the account level.  
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/resource-ids.html

Didier_Durand · Accepted Answer

Hi Riku,

I would tend to say that they are globally unique: https://www.amazonaws.cn/en/ec2/faqs/

`Each ID is unique and will never be reused.`

```
Only resources that are created after you opt-in to the longer format will be affected. Once a resource 
has been assigned an ID (long or short), that ID will never change. Each ID is unique and will never be 
reused. Any resource created with the old ID format will always retain its shorter ID. Any resource created 
with the new format will retain its longer ID, even if you opt back out.
```

If you think about AMI ID (covered by same definitions as EC2 instances, you can share them across accounts. It reinforces the needs for global uniqueness.

Best,

Didier

Marcos Ortiz · Answer

According to the EC2's FAQs is extremely improbable that will happen: https://www.amazonaws.cn/en/ec2/faqs/

nitin babariya · Answer

No need to worry! EC2 instance IDs in AWS are like fingerprints – each one is unique and special. 
You won't run into a situation where your EC2 instance ID is the same as someone else's in a different AWS account.

AWS makes sure that every instance ID is distinct, so you can easily manage and track your instances without any confusion. It's all part of AWS's effort to keep things organized and straightforward

Is there a possibility that an EC2 instance ID may duplicate an ID with another account?

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