National Insurance Number for foreigners eCommerce sellers

Hello, my client has an eBay seller account in the UK, he has an LTD registered and attached to his eBay account. He is a resident of the USA. Please help me with how we can apply for the National Insurance Number as eBay payouts are on hold for our account. Also, help me if there's an option to get an NI number if the foreign seller doesn't have an LTD registered. Thank you very much for your help

Hi,
Either you or your will need to put a request in writing to obtain a liability decision for UK tax and National Insurance purposes. Please write to:
PT Operations North East England,
HM Revenue and Customs,
BX9 1AN
The information we require is as follows:

• Full name
• National Insurance Number
• Date of birth
• The date they left the UK, if applicable
• Your most recent UK address
• Your address abroad, if applicable
• The type of work they do
• Your company name and address – UK and abroad
• Where their contract is held
• How often they work in the UK
• Your normal working pattern (the days, weeks or months they regularly work)

Thank you.