Why are my Mastercard transactions posted to my account at a later date?

Mastercard transactions have 2 steps in each transaction.

The first step is when you make your purchase/payment at a merchant/ATM and authorize the bank to debit the funds.

The second step, which can happen days after, is when Mastercard confirms the transaction with the bank and we debit the actual funds from your account.

This is why the transaction is posted to your Tonik account at a later date.