Yesim offers unlimited‑data eSIM plans for Serbia that cover 3G and LTE networks. The provider sells these plans in a range of validity periods: 1 day for $8.21 USD, 7 days for $28.16 to $30.50 USD, 15 days for $41.06 to $53.97 USD, and 30 days for $50.45 to $65.70 USD. All unlimited plans allow tethering, but the description notes that speed may be throttled and that a Fair Usage Policy applies, meaning data speeds can be reduced after heavy usage.
Because speed throttling is possible under the Fair Usage Policy, travelers who need to avoid potential speed restrictions should contact Yesim directly to confirm how the policy is applied and what data volume is typically available at normal speed for each plan.