So if you withdraw or deposit money into your own bank account in another province you have to pay a service charge.

If you do it through an ATM, (Bangkok Bank to Bangkok Bank) there is no fee, but it is limited to 50k per day.

What about in branch transfer, do they still charge a fee then when no cash is actually being moved?

See fees listed at this Bangkok Bank Link.

Found a nice little loophole that works.

A branch can change the daily limit to 500,000B to move funds between 2 accounts (same name) through a ATM. then you just pull it out over the counter (if ore than the ATM limit) and no fees. Yippee

Done it, it works.

Depends on your bank and type of account too. I don't suffer many inter-province charges at all with Stan Chart and TMB. BBL like to charge tho'!

Cheers

Fletch