The following information is from the Government website with regards to the Apprenticeship Levy:

When you need to pay it

As an employer, you’ll have to pay Apprenticeship Levy each month from 6 April 2017 if you:

– have an annual pay bill of more than £3 million
– are connected to other companies or charities for Employment Allowance which in total have an annual pay bill of more than £3 million
– Your annual pay bill is all payments to employees that are subject to employer Class 1 secondary National Insurance contributions such as wages, bonuses and commissions.

You must include payments to:

– all employees earning below the Lower Earnings Limit and the Secondary Threshold
– employees under the age of 21
– apprentices under the age of 25

Your pay bill does not include earnings:

– of employees under the age of 16
– of employees who are not subject to UK National Insurance contributions legislation
– on which Class 1A National Insurance contributions are payable, such as benefits in kind

How much you need to pay

Employers who are not connected to another company or charity will have an Apprenticeship Levy allowance of £15,000 each year.

The allowance reduces the amount of Apprenticeship Levy you have to pay by £15,000 across the year. This means that only employers with an annual pay bill of more than £3 million will pay the levy.

You cannot carry over any unused allowance into the next tax year.

Connected companies or charities will only have one £15,000 allowance to share between them.

If you start or stop being an employer part way through the tax year you can use your full annual Apprenticeship Levy allowance against the amount of the levy that you owe.

For more information please see:
https://www.gov.uk/government/publications/apprenticeship-levy-how-it-will-work/apprenticeship-levy-how-it-will-work#pay-apprenticeship-levy