Company seats registration flow – looking for alternatives/opinions

I'm trying to verify whether the company seats registration flow I built makes sense or not and I'd like to hear about other ways/options/flow.

As a part of my SaaS product, I want companies to be able to purchase one of three packages. Each package provides a different number of seats, as shown below:

  • Plan A: 5 - 10 members
  • Plan B: 11 - 50 members
  • Plan C: 51 - 100 members

The current sign up/registration flow is as follows:

  1. Company's representative (e.g. head of HR) selects a package which reflects the amount of seats needed for the company
  2. The company's representative provides details: name, title, phone and email address which must be with the organization's email suffix (e.g. @mynicecar.com)
  3. Payment form: the company's representative completes the payment
  4. Once the payment is confirmed, each user who signs up with his organizational email address (e.g. john@mynicecar.com) will automatically get permission to the product with no need for pay as it uses a seat from the seats pool

Any other flows you can come up with? Maybe implementing a coupon/code based seat management (each time a code is used, it's being taken from the pool) instead of tying it to the organization's email suffix, etc...

Thanks.