If you’re subject to a tapered Annual Allowance, only part of your tax charge can be on a Mandatory basis. If you have missed the 31st January deadline, you may wish to split your tax charge into Voluntary and Mandatory, as Mandatory has a later payment deadline (please see front of form). We cannot assist you with this calculation.
See www.gov.uk/hmrc-internal-manuals/pensions-tax-manual for further details.