The 31 January 2019 is not just the final date for submission of your self assessment tax return but also an important date for payment of tax due. This is the final payment deadline for any remaining tax due for the 2017-18 tax year. In addition, the 31 January 2019 is also the payment date for any Capital Gains Tax due in relation to the 2017-18 tax year and the due date for the first payment on account for 2018-19.Taxpayers that do not have the necessary available funds to make these payments should be pro-active and contact HMRC as soon as possible. Pretending the problem does not exist will not make the problem go away and can only make matters worse.Taxpayers will need to contact HMRC to apply to make a payment plan and seek to agree a way forward. This can be done by contacting the Business Payment Support Service (BPSS). The BPSS was first launched back in 2008 and is available to all taxpayers (not just businesses). The purpose of the service is to provide support to those experiencing a wide range of tax problems.The services offered by the BPSS depend on individual circumstances but can include:agreeing instalment arrangements suspending any debt collection proceedings reviewing penalties for missing statutory deadlines reducing any payments on account agreeing to defer payments due to short-term cash flow difficultiesThe BPSS will review the issues raised and look sympathetically at providing a practical solution. HMRC will usually not charge additional late payment surcharges in relation to specific arrangements made using the BPSS.