Where can I find a witness stamp for my client declaration while in Thailand?

Greetings

Can anyone advise please?

The Customer Service Officer for International Centralised Services International here in NZ has indicated that a client declaration (standard form) needs to be completed every 6 months while away overseas to ensure continuation of Superanuation payments.

This declaration requires a witness signature, and if to be e-mailed in return also requires a stamp.

The stamp must show the city/country that the witness is in.

If you post the form, you do not need to have it stamped by the witness as the postal stamp will show this.

Can anyone advise where such a stamp may be located, or offer advise pl.

Thanks