What is the best value prepaid SIM card available for someone who uses his phone very infrequently? Is there a card with no time limit?

I've never used a SIM in Thailand and don't know anything about what's available. Thanks for any guidance.

I use 1-2-Call from AIS

Okay, I googled 1-2-Call. Seems it expires 90 days after your last activation. Is there a card that doesn't expire, or gives you more time to use your credit?

Okay, I googled 1-2-Call. Seems it expires 90 days after your last activation. Is there a card that doesn't expire, or gives you more time to use your credit?

for 300baht you get 1 month Extension

on 12call ...

on ORANGE you will get 3!month

Use 1000 baht orange card---good for six months

Top it off until it gives you an appropriate expiration date.

Is there a card that doesn't expire, or gives you more time to use your credit?

No, if you are really an infrequent user you will eventually be buying "days of lifetime" while the minute balance shoots up with refills you never use.

Either get used to this, and shop in terms of baht/month, or find a chatty friend who places long calls to family and friends and let them use your phone one in a while and top off at a slightly discounted rate over what they get on their own phone. They get their slightly cheaper minutes, and you get your expiration date pushed out.

There are no cards that never expire, but most of the companies have plans that will give you longer time per top-up. IE, I use 1-2-call, and it has a plan called "sawasdee" that give you double the time credit. Usually for 300 baht you get 30 days, but in this you get 60 days. 800 baht gets you 200 days (800 baht cards are no longer sold, but you can do over-the-counter top-up). So 1 year costs around 1,300 baht, which isn't bad. You can still call anyone for 5 baht/minute, and anyone can call you.