Will there be different entry checks on UK nationals when entering the EU?
Yes, UK nationals will be treated as third-country nationals as of the end of the transition period. There is no legal alternative under the Schengen acquis. This means that the entry conditions for third-country nationals and the procedures applicable to the crossing of the EU external borders will also apply to UK nationals, as will the relevant provisions of the Union Customs Code and directives relating to VAT.
Concretely, this means that: UK nationals will no longer be able to use the designated lanes at Border Crossing Points (EU, EEA, CH); their passports will be subject to stamping upon entry and exit from the Schengen Area; they will be subject to checks including checks against databases upon entry and exit; they will be subject to the EU’s Entry/Exit-System (EES) and the European Travel Information and Authorisation System (ETIAS) when these systems will be deployed in the future.
The entry checks on UK nationals will include verification of the possession of a valid travel document for crossing the border; the duration of the stay; the purpose (e.g. tourism or work) and the conditions of the intended stay (e.g. accommodation, internal travels); the existence of sufficient means of subsistence (i.e. having sufficient means to pay for the intended stay and return travel).