Which exchange rate is the official one in Latvia?
The official rate is the European Central Bank reference rate, which the ECB publishes each working day at about 16:00 Latvian time. It is the rate the State Revenue Service uses for accounting and tax, and it is the same across the euro area.
Why does the bank give less than the published rate?
Because the ECB reference rate is an averaged market indicator, not a price anyone trades at. A bank buys lower and sells higher, and the spread is usually one to three percent — more at an airport bureau. That spread is the fee.
Which rate applies to an invoice in a foreign currency?
Latvian accounting uses the ECB reference rate in force at the start of the transaction day — that is, the one published the day before. The State Revenue Service applies this to income and expenses alike, and a bank's own rate will not do.
Why does this calculator show no rate?
Because we do not show a figure we cannot back with a source. Rates move every working day, and a stale rate looks right without being right. Until the ECB daily rate is fetched automatically, the calculator names the missing figure and points at the ECB page.