I am in my early 30s. I added it because I was worried that they wouldn't accept my bank statements alone, since I only transferred the money into my account a few days prior to applying, and my bank statements only showed regular payments being made into my account during the first half of the year, before I changed my job.
Some things I read had on third party websites suggested that the money needed to be in your account for a while, so I asked my dad to write me this just in case.
I'm not sure if it helped or not.
IIRC you don't even need to provide your own bank statement if your parents are willing to support you. You can provide their bank statement, and a copy of birth certificate.
I opened a bank account on my second try after arriving in Thailand at the start of this year.
No work permit, no certificate of residence, just ID and a TM30 from my hotel if I recall correctly.
I was on a Multi Entry Tourist Visa at the time.
Went to a shopping mall, walked into one bank, they turned me away, walked into the next bank (KrungSri), and they opened an account for me on the spot.
Try your luck at a few different banks, or even different branches of the same bank.
If you don't have any luck you could also try and agent as others have mentioned, maybe I got very lucky idk.
Now I'm on DTV and I transfer money from my Wise into my Thai bank account as I need it. No issues with tax so far and have been doing this regularly since opening my account. Usually transfer 49k baht at a time as my account has a 50k baht per day daily transfer limit.