Since December, Serbs have not needed visas for the Schengen zone
A new visa code has come into force in most EU member states, speeding up and standardising visa procedures for travellers to Europe.
The new rules apply to the 25 countries in the Schengen zone, where people can cross borders without passport checks.
Schengen embraces 22 EU countries and three non-EU nations - Norway, Iceland and Switzerland. The UK and Irish Republic are among those outside.
Getting a Schengen visa will be "faster and fairer", the EU Commission says.
The code applies to third-country nationals seeking a short-stay visa for travel within the zone - that is, valid for 90 days. Visas for long stays - beyond 90 days - remain under national jurisdiction.
The European Commission says the visa code is now being applied by Schengen countries' consulates worldwide.
The code sets a maximum deadline of two weeks for states to interview a visa applicant. Then officials have to decide within 15 days whether or not to grant a visa.
Currently officials do not have to explain a refusal to grant a visa, but from 5 April next year they will have to give a reason. Disappointed applicants will have a right of appeal.
The code also introduces a reduced visa fee of 35 euros (£31; $47) for children aged between six and 12. The normal fee is 60 euros.
Citizens of countries that have visa facilitation accords with the EU will also pay only 35 euros.
The new code "will ensure that the application of EU visa law is fully harmonised", EU Home Affairs Commissioner Cecilia Malmstroem said.
EU data shows that in 2008 the Schengen zone issued nearly 10.4 million visas. The largest country totals were: Germany (1.77m); France (1.74m); Italy (1.2m); Spain (802,032) and Finland (792,277).
In December the Schengen countries granted visa-free travel for citizens of three Balkan countries - Macedonia, Montenegro and Serbia. All three are seeking to join the EU.
The five EU countries that remain outside Schengen are: the UK, Irish Republic, Bulgaria, Romania and Cyprus.