Follow this steps and you will able to open an Merch by Amazon account easy:
The first step is to head over to https://merch.amazon.com/landing and click on the request invitation button. You can read around and see exactly how the entire process works. It will then ask you to sign in to your Amazon.com account. If you do not have one, you will need to create one Like shown Below:
Then Start fill out the application, you will need a few things. These include your business contact information, your bank account details (account number/routing number), as well as be prepared to fill out a tax questionnaire.
You are going to fill out these pages. These are the company profile, payment & banking, and tax information.
If you do not have a company set up, You will be putting your personal name instead.
Enter in your REAL Full NAME
Enter in your bank details and then take the tax questionnaire.
If you are not from the USA, you may need want to avoid the 30% tax withholding.
Once you have finished up that page click submit!
after submitting the application all you need is to wait for amazon to send you a letter of approval ( if they denied you application they will let you know too). The time may take from 2 days to 1 year! so be patient.