We use the monthly ECB (European Central Bank) GBP to EURO Exchange rate. This is the static reliable rate only updated on the 1st of each month which the EU use to determine value for customs purposes. It does not fluctuate like the second to second rate you’ll find on Google or Xe.com for example.

As of this month the ECB exchange rate is 1 EUR = 0.86643 GBP

The IOSS threshold of 150 EUR = 129.96 GBP using this months rate.