How the Stay Authorization Works
You won’t need to apply for a stay authorization. You will get a stay authorization when you show up at a border control checkpoint at a land border, an airport or a seaport. A border control agent will put an entry stamp in your passport and will write down “T-90” or “T-180”. These are the number of days for which your stay authorization has been granted. From this day on, you can stay visa-free in Ecuador for 90 or 180 days during the following period of one chronological year (365 days). Below, I will use the term visa-free day because this makes things easier to understand.
Every day that you are in Ecuador, you will consume one of these 90 or 180 visa-free days. You can visit and stay in Ecuador without having a visa as many times as you want during your chronological year as long as you haven't finished all 90 or 180 visa-free days
Your chronological year ends 365 days from your first date of entry. When your chronological year ends, your unused visa-free days expire. This means that you'll need to leave Ecuador on this day or before this day.
The next time that you visit Ecuador, you will receive 90 or 180 new visa-free days to visit Ecuador during a new chronological year of 365 days. This new chronological year starts on the date of your new entry to Ecuador.
An example
Let’s assume that you are an US citizen. US citizens get a stay permission for 90 days (90 visa-free days). You arrived in Ecuador for the first time on February 8, 2024, and you left the country on February 15, 2024. This means that you have consumed eight days of your 90 visa-free days and that you can still visit Ecuador for 82 days until February 7, 2025, without having a visa.
Let's assume that you revisit Ecuador from July 4 to July 10, 2024. Now you have consumed seven more visa-free days. The result is that you can still visit Ecuador for 82 -/- 7 = 75 days until February 7, 2024, without having a visa.
Now let's assume that you want to visit Ecuador for the third time on March 5, 2025. At this time, you will have 90 visa-free days to spend in Ecuador until March 5, 2024.
Another example
Let’s assume that you are an US citizen. US citizens get a stay permission for 90 days (90 visa-free days). You arrived in Ecuador for the first time on July 10, 2024, and you left the country on July 15, 2024. This means that you have consumed 6 days of your 90 visa-free days and that you can still visit Ecuador for 84 days until July 9, 2025, without having a visa.
Let's assume that you revisit Ecuador from July 4, 2025. You still have 84 visa-free days but they expire on July 9 (the end of your chronical year). This means that you must leave Ecuador before or on July 9. You may re-enter Ecuador on July 10. Your new chronological year then starts and you'll get 90 new visa-free days.