Being the holder of a foreign currency account with TMB and also a long term resident of Thailand, I'd like to know if it's possible to have the fifteen percent withholding tax payments, on the interest, which are currently collected by the bank at interest payment time, suspended.

It would be nice to have the option of paying it myself, not by the bank, at my annual Thai income tax return filing time

If it can be done, what paperwork would I have to show to the bank?

I've emailed the bank and their response was to phone the bank's call center, however the call center's staff English was lacking and they couldn't grasp the phrases 'withholding tax or foreign currency account'.

My next available path of inquiry would be to find and go to a branch which has English speaking staff. This may be time consuming and frustrating as it would be hit-and-miss locating fluent staff.

When I do find out whether or not it's possible, then I'll consider going direct to the bank's head office in Ladprao and then submitting the necessary paperwork.

I am not sure, but I very much doubt it's possible. The whole idea of withholding tax, is that it is withheld at source.