Technically, an S-corporation does not need a tax ID. However, it is recommended that an S-corporation have one. Tax IDs/EINs can be complicated, so it’s important to make sure you have everything you need when creating a new company.
Tax IDs/EINs are not acquired when a company is first formed, and they aren’t required at that time. However, they are required when the company wants to hire employees, or when the company needs to file a tax return. So, even though an S-corporation might not “need” a tax ID, functionally it’s going to have to get one eventually.
An S-corporation without any employees or business bank accounts could theoretically avoid getting a tax ID until it has to pay its taxes. An S-corporation with only one proprietor can pay taxes through an SSN. But eventually, an S-corporation is going to need a tax ID on a pragmatic level. Moreover, it’s not difficult to get. Getting a tax ID requires a single form, which can be submitted online, and which can usually be returned with a tax ID within an hour.