We are British Expats living in the Netherlands since 2011 going to China

Barbara, your husband needs to apply for the Z type. His employer should assist him to get the work permit first. With this permit, he can apply for the Z type. After he arrives, he has to change the work permit into the Alien's Employment Certificate / Foreign Expert Certificate. Then he has to change the Z into the resident permit within 30 days since his arrival.

For you, you need the invitation letters from your husband and his company, copies of his passport information page and resident permit. It means that you need to apply for the S1 type after your husband acquires the resident permit for Z type. Besides, your marriage certificate is also required when you apply for S1.

Forget to say, if you both apply in Netherlands, you both need to provide your resident permit or any other legal proof that can prove you reside legally in Netherlands.