Reverse charge VAT on US invoice with GB VAT code

I have received two invoices for digital services from Zoom and another company, both US based, with GB VAT codes.  Both say that "VAT should be self-accounted for under the reverse charge mechanism".  I am familiar with reverse charge for EU-based companies through MOSS VAT, but not a domestic reverse charge.  How do I code this for VAT in QBO?  Thanks.