The idea of a "Tech Tax" is ridiculous. People talk about needing to tax some businesses on their sales. This is a taxation method born of madness.
Some businesses reduce their taxable profits by moving their profits into nil or low tax jurisdictions by having subsidiaries in low tax jurisdictions charging subsidiaries in higher taxed jurisdictions for "royalties" and "interest".
I would suggest that the way to counter this would be to add back to "high tax subsidiaries" taxable profits these expenses to the extent that the "low tax subsidiaries" have their tax reduced.
For example: Country A has a tax rate of 20% and country B has a tax rate of 5%. Subsidiary in country B charges subsidiary in country A £4m of royalties. The subsidiary in Country A has £3m (75% of £4m) of royalties added back to their taxable profits.
There could be a materiality test to not make the research for the calculations too onerous.
Is this a sensible solution?