Employers of helpers are required to pay a monthly levy via a General Interbank Recurring Order (GIRO) account throughout the duration of the employment contract.
Once you have applied to create the account, it usually takes 3-4 weeks after you send the GIRO Form to be implemented.
You can check your GIRO application status on CPF website. Under section 1, you can key in your NRIC/FIN number and get the update.
Then, the levy for each month will be deducted from your bank account on the 17th of the following month (or the next working day if it falls on a weekend or public holiday). Further information on MOM's website.