Bill in every currency, report in one
Invoice a Berlin agency in euros and a Chicago client in dollars, and still read a single revenue figure in the currency your tax return is written in.
The three to five percent nobody puts on an invoice
The customer research behind this product puts currency conversion charges at between three and five percent of cross-border freelance revenue, which on fifty thousand a year is somewhere between fifteen hundred and twenty-five hundred. LingoDesk does not move money and cannot reduce that figure by a single unit; saying otherwise would be a promise no software here can keep. What it can do is stop the figure being invisible, by recording what left in the client's currency and what arrived in yours, so the gap becomes a line you can read rather than a vague sense that the bank took something.
Written in the client's currency, in the client's conventions
The currency a client is billed in lives on the client record, and every invoice raised for them is issued in it and formatted the way that currency is written: the separator, the position of the symbol, the number of decimal places. The document language sits on the same record, so a Munich agency receives a German invoice and a Lyon one receives a French invoice without either being assembled by hand at the end of the month.
Which rate applied, and on which day
This is the question that ruins a January. An invoice raised in June and settled in August has at least three defensible conversion rates and a tax authority expecting exactly one. So each invoice records the rate that applied at the moment it was raised, together with the resulting total in your home currency, and both are stored on the invoice itself rather than recomputed afterwards. A reconciliation in the new year then reads what was true at the time, instead of depending on a historical rate looked up eight months late.
One revenue figure at the end of it
Because every invoice carries its own recorded rate and its own home-currency total, the year adds up in one currency without anything being converted twice. That total then breaks down by month, by client and by language pair, which is the only thing that makes a euro-denominated agency and a dollar-denominated direct client comparable at all, and the only reason the profitability question on the reporting page has a defensible answer.