The interface is English only. There is no translated version of the site, and every email, help article and video is in English. What is not tied to the United States is the money.
Currency and number formatting
Open My Account and choose your locale. Undebt.it uses that setting to render every amount on the site: the currency symbol and where it sits, the thousands separator and the decimal mark. A member in Manchester sees £1,250.00, a member in Berlin sees 1.250,00 €, a member in Sydney sees A$1,250.00. The math underneath is the same; only the display changes.
Undebt.it does not convert between currencies. All of your accounts are assumed to be in the one currency your locale implies, which is how nearly everyone's debts work anyway.
Date formats
Dates follow the same locale setting, so due dates and payoff dates show as day-month-year where that is the local convention.
Interest rates and payment rules
The plan engine works on balance, rate and minimum payment, none of which is country specific. Members outside the US use the site every day for credit cards, personal loans, car finance and student loans. One thing worth knowing: some UK and Canadian loans quote a balance that already includes future interest.