frictionless

Of or pertaining to lack of friction.

It would last many years because of its frictionless bearings.

A hard border is a real possibility, and a frictionless border is almost an oxymoron.

Of a transaction or trade, without tariffs and non-tariff barriers.

"There can be no frictionless trade outside of the customs union and the single market," said Donald Tusk, president of the council of all 28 EU member states.