Is the Contact ID unique between all HubSpot accounts?

[kizus]

Hello everyone,

I know that there is this endpoint below:

GET/crm/v3/objects/contacts/{contactId}

that retrieves a contact object identified by the given contactId in a specific HubSpot account (identified by the provided access token). 

If I send a request to the same endpoint but changing the HubSpot account (which means a different access token) there is the possibility of retrieving another contact object (from a different account but with the same id)?

I ask that because my main concern is: The contactId is unique between ALL HubSpot accounts, or it is unique only considering a given HubSpot account?

[Crystal_Hopper]

Following! Interesting question.