Mouser to the UK....plus 20% soon

Look at your invoices, VAT is added already and always has been. Claim it back in the usual way if you are VAT registered.
I realize that orders from the EU will have VAT added; Order from EU at present for the UK and VAT is not taken at source if you supply your VAT number. This will change in the New Year and VAT will be added and can then be reclaimed when it arrives in the UK.