Most European citizens do not need a visa to enter Serbia. Visas are not required for citizens of the United States, Canada, Israel, Singapore, Japan, Australia, and a few other countries for stays of up to 90 days. Citizens of the EU, Bosnia and Herzegovina, FYR Macedonia, and Montenegro only need an ID card. For up-to-date and comprehensive information, contact your closest Serbian embassy.
Serbia has declared that travellers possessing Kosovan visas or passport stamps would be denied entry. This is not yet the case, however the visas and stamps will be overstamped with a “cancelled” stamp. Be aware that entering Serbia through Kosovo without a Serbian entry stamp is deemed unlawful and may result in severe fines; nevertheless, departing Serbia via Kosovo is not an issue.
Customs procedures are very simple, but one noteworthy restriction is that you are only permitted to transfer 120,000 Serbian dinars into and out of the country, and notes bigger than 1000 dinars are not permitted to cross the border. You may bring up to ten thousand euros across the border without declaring it. Because bank transfers from Serbia are still cumbersome, cash is still the most convenient alternative for medium-sized amounts.
Foreigners, like those in neighboring Bosnia and Croatia, are obliged by law to register with the police station in their area within 12 hours after obtaining a Serbian entrance stamp at a border crossing or airport.
When you check in at a hotel, the staff automatically registers you; but, if you are staying with friends in a private residence, you must register your presence with the police in the area in which you are staying.
If you register at a police station, you should be given the bottom half of the Foreigner Registration Form to take with you, or a printout from hotel reception if you are staying at a hotel; before leaving the country, you may be asked to show it to the Border Police. They may not always ask for it, in which case you may retain it as an administrative memory. Remember that failing to register may result in prosecution and a hefty fine, but this is seldom enforced.