She said eight years ago Auckland made the same transition and found only 12 per cent made the switch.
For Hawke's Bay, most estimated they would get between 20 and 25 per cent sign up.
Kirton hoped the change would prevent the number of cheques that went un-cashed, but reassured people that if they hadn't signed up they would still get the annual cheque in the post.
"We have had a few in the past where people haven't cashed in their cheques so it just stays in the trust fund, which has been a substantial amount, and then they have to pay to have them reissued again."
Those who are still using the cheque system are warned if they end up having to reissue their cheques it will cost a lot more than previous years.
Registration for the direct credit system ends on Friday and those who have signed up will receive direct payment by Monday. Cheques will be sent from Monday onwards.
The opportunity for registration will become available every year for those who have not yet done so.
• To register you can call 0800 535 738 or visit the trust's website.