You can't lose your merits but can lose your sMerits if you don't spend it in 30 days if you are merit source.
You need to specify that only merit sources will experience like this but in normal users, it will never expire even though they are hoarding on it.
But this was stated when you are trying to send merit, you will see there this line, "
There is no point in hoarding sMerit; keeping it yourself does not benefit you, and we reserve the right to decay unused sMerit in the future. ". The last part was not yet implemented. Which is your unused smerit will decay in the future for normal users.
Merits and smerits are 2 different things and you can't compare it.
That's right and in
smerits,
s stand for sendable, so it means sendable merits.