During the sign up process, you'll be asked to indicate if you already make Provisional tax payments (you can also indicate this in the 'Financial Details' section of your Dashboard).
What is Provisional Tax?
At the end of the Financial Year, if you have to pay more than $2,500 in legacy tax, you will be required to make Provisional Tax payments in instalments throughout the subsequent Financial Year. In essence, these payments are IRD's way of helping you overcome past tax bills.
If you are already subject to Provisional Tax payments, Hnry will make regular contributions towards these whenever you get paid, helping you get off Provisional Tax. Do keep in mind, you may still be responsible for making partial Provisional Tax payments if your Provisional Tax payments are higher than the contributions paid through Hnry.
N.B.: Once ALL your income has come through Hnry for a period of time, you will not need to retain any funds for Provisional Tax.