VAT settings for submissions

When a Ltd company is registered for VAT and the tax agent ticks the “Enable Online Filling” for vat return submissions by a tax agent the username and password is obviously the tax agents, but who’s postcode is entered in the “Registered Postcode” box.

Is it the Agents registered postcode?
the Ltd companies registered office postcode?

It should be trading address postcode registered with vat application

Thank you, much appreciated.