This deadline is relevant to employers who have made PAYE deductions from their employees' salaries and to contractors who have paid subcontractors under the CIS.
Employers are required to make payment to HMRC of the income tax, national insurance and student loan deductions. Contractors are required to make payment to HMRC of the tax deductions made from subcontractors under the CIS.
Where the payment is made electronically the deadline for receipt of cleared payment is Friday 21st December 2018 unless you are able to arrange a 'Faster Payment' to clear on or by Saturday 22nd December. In year interest will be charged if payment is made late. Penalties also apply.