This is more effective for one-off or seasonal imbalance of international payments. For example, a country uses changes in official reserves or temporary borrowing of short-term funds to offset excess foreign exchange demand or supply to cope with the short-term imbalance of international payments.

For example, Iceland has a special sardine export (like hairy crabs, it is caught and listed every autumn). Therefore, Iceland's seasonal foreign exchange supply will surge in autumn, and Icelandic fishermen need domestic currency for consumption, not foreign currency. Therefore, the Icelandic government can pay Icelandic fishermen the national currency of the central bank, while the Icelandic central bank holds foreign currency or buys international bonds as foreign exchange reserves to offset the payment demand of domestic exporters for domestic currency when this foreign exchange supply suddenly increases.

If the country in the above example has no foreign exchange buffer policy (foreign exchange reserve), then the exporters of sardines from Iceland will spend a lot of time on the compensation and settlement of international goods, and finally compensate and settle the exported sardines with foreign goods (for example, taking back hairy crabs from China).

The foreign exchange buffer policy can be roughly described as follows: surplus-demand for foreign exchange-leads to buying foreign exchange; Selling foreign exchange at a deficit.

In fact, the foreign exchange buffer policy is an efficient international trade behavior for central banks to settle commodities in currency instead of commodities.