Mr Bull said these could once again be restricted to UK citizens/residents and companies.
Following the UK’s exit from the EU, Mr Bull said VAT might be expected to continue in the UK in much the same way although it will be necessary for tax law to be changed to confirm that relief for import VAT will continue to be available.
He said there may also be issues with output VAT which could harm UK exporters unless a mechanism is developed to allow EU importers to reclaim import tax in much the same way as they do now.
After exit, Mr Bull said the interpretation of VAT law in the UK would not be bound by the European Court of Justice.
Even if UK VAT law does not change, Mr Bull said there could well be changes in the way HMRC applies VAT in the UK.
Specifically, he said the taxation of cross-border transactions may change.
Although the EU is developing plans to extend the “One-Stop-Shop” mechanism to non-EU suppliers of online sales of goods, Mr Bull said it is likely that many UK traders will, nevertheless, have to register for VAT in each country in which they trade.
Once the UK has left the EU, Mr Bull said some EU tax developments will proceed without UK influence.
He said this includes the EU Financial Transactions Tax as well as the Common Consolidated Corporate Tax Base.
Mr Bull said: “The next few years promise to be very challenging for individuals, businesses and tax practitioners alike.”
Before the chancellor’s statement this morning, the pound fell further in trading in Asia, down another 2.6 per cent against the dollar at $1.34.
In early trading on the London stock market, the benchmark FTSE 100 index fell nearly 1 per cent before recovering some lost ground.