HMRC letters to overseas companies

Does HMRC send letters to a company’s UK establishment office address or to the overseas company address?

Hi
HMRC can send letters to an address in the UK or abroad.
It depends on what address we hold on our systems.
Initial registration letters or authorisation codes are always sent to an employer's business trading address for security reasons.
If the address is abroad, the letter can take up to 28 days to be received.
If the address is in the UK, the letter should be received within 3-5 working days.