This article introduces how to change the domain automatically generated in the "〇〇.myshopify.com" format when you create a Shopify account, along with important points to note when making the change.
If you haven't opened a Shopify account yet, please refer to the blog article below.
What Is a Shopify Account ID?
In this article, we refer to the 〇〇 portion of the domain automatically generated in the "〇〇.myshopify.com" format when you create a Shopify account as the Shopify Account ID (or account number).
How to Change Your Shopify Account ID

(1) From the admin, go to "Settings > Domains"
(2) On the Domains page, click "Change new myshopify.com domain"

(3) Enter your new Shopify Account ID
(4) Click "Add domain"
Points to Note When Changing Your Shopify Account ID
You can only change it once

As noted in the Shopify Help Center, you can change your "Shopify Account ID" only once. For this reason, be sure to carefully check for any input errors before making the change.
Reference: Adding business settings to your store | Shopify Help Center
It may affect Shopify apps and themes
Some Shopify apps and themes manage licensing based on the "Shopify Account ID." If you change your "Shopify Account ID," your contract may be cancelled, or the apps or themes you're subscribed to may become unusable. Before making a change, be sure to check with the app or theme developer to confirm there will be no impact.
Some development stores cannot change it

If a development store was created in a way that, for example, automatically generates test data and therefore cannot be transferred, you cannot access the Domains page itself, and so you cannot change the Shopify Account ID.
Summary
Your Shopify Account ID (the 〇〇 portion of 〇〇.myshopify.com) is an important identifier for your store. While it can be changed, be aware that it can only be changed once. The change process is relatively simple and can be done from "Settings > Domains" in the admin, but it is an important operation that should be handled carefully.
When considering a change, first make sure to thoroughly double-check your new ID to minimize the risk of input errors. It's also important to investigate in advance the impact on any apps or themes you currently use. In particular, if there are apps or themes that manage licensing based on your account ID, changing it could cause problems afterward.
As a point of caution, you cannot change your account ID on a "development store that cannot be transferred." Keep this kind of restriction in mind as well.
Changing your account ID is an important decision that can have a significant impact on your store's operations. For this reason, it's wise to fully consider whether the change is necessary, carefully check the scope of impact, and then proceed. With proper preparation and understanding, you can make a smooth account ID change.
