I'm still rather surprised to see someone write that importing from outside the EU is no harder in terms of admin than importing from within. Surely importing from elsewhere within the EU needs very little admin at all, so if goods crossing the EU border are also not a big deal in practice, why do you think parts of our business community are so concerned about the overheads of trade with the EU post-Brexit if we wind up outside the SM/CU?

Because you loose the systems of the CU that make it so easy! It is easy to import into the customs union because

1) It is worthwhile to other countries to make specific agreements with the EU, because you make them once and they are valid for the EU28. Many countries have these deals with the EU.

2) As another poster mentioned, once goods are cleared for the EU they can shop to any EU country.

3) The common commodity code system means that once you have established what code your goods fall under you can send them to all 28 countries.

4) Outside of the CU we would have to have our own customs agreement with every country in the world. Develop our own systems, commodity codes, standards, IT etc.

5) Outside of the CU we would have to agree Tariffs with every country in the world rather than CCT

6) Outside of the CU our goods will have to clear customs into and out of the EU. Most UK goods currently ship to Calais which is not a customs port and has no facilities for this. I don't see the incentive for France to build them either.

7) Outside of the CU goods attract VAT when they clear customs. Whilst you can claim it back, there is a catastrophic cash-flow impact for importers.

8) None of this is agreed yet with 1 year to go!

9) UK has land border with Ireland that is totally open and must be so under the Good Friday Agreement (for those that don't know this is a fundamental treaty of the peace process in Northern Ireland), of which the USA and EU are co-guarantors. The Customs Union is what allows this to work. Without it you have to have customs because goods in Ireland are now free to move across the EU. The UK government has already agreed to keep 'regulatory alignment' (a customs union) with NI to allow this to happen in the November deal (which it seems to be pretending didn't happen right now). Under the agreement between the Conservative party and the DUP whatever agreements are made must cover the whole UK or they withdraw co-operation and the government falls.

Interesting how this plays out....I suspect we will have a CU with a different name as a fudge.

RE: Services I would be more concerned than goods. Professional qualifications are currently good for the whole of Europe. Chartered Accountant or Engineer you can practice in all 28 states. Not so after Brexit. If you are selling to consumers then you will have to abide by all of the the same standards and rules as the EU sets, but not get any say in them any more.

So yes it is much simpler to be in the Customs Union.

One theme seems to be that the CU is convenient for those importing to or via multiple EU countries, because you have the same rules to comply with wherever you bring the goods in and then once inside they can go anywhere else inside.

Another seems to be that a UK outside the CU would have to make its own arrangements with trading partners, including the EU at that point, and everyone would have to implement any necessary customs checks at borders, including the Irish border and ports of entry for UK goods into the EU.

Finally, there are a couple of separate issues, in terms of the VAT/cashflow issue and the timescales for figuring all of this out.

Is that a fair summary?