Once you have completed the registration you will be asked to complete a tax return on an annual basis for the period 6th April to 5th April retrospectively.
You will need to ensure that you submit your tax return by 31st October (if you are filing by paper) or by 31st January (if you are filing online) following the end of the tax year.
You will also need to make sure that you pay any tax liability due by 31st January following the end of the tax year.