Payment of customs and excise duties (but not import VAT) is normally “deferred” by importers, warehousekeepers and representatives. If there is no duty deferment facility available HMRC will require immediate payment.
The importer may use the deferment account of a 3rd party such as a logistics provider, customs agent, tax representative or warehousekeeper to pay any customs charges due to HMRC if they have specific permission from the account holder to do so – this permission can be inferred where the account holder is also the  person making the customs declaration (the “declarant”). The deferment account holder, if not the importer, will usually charge a fee (in addition to any other fees) for use of their deferment facilities and seek re-imbursement of the duty charges by means of a remittance invoice.
In practice duty deferment means that payment of any duty (etc) charges incurred in a given month will be taken by HMRC from the deferment account holder’s (or their representative’s) bank account on the 15th day of the month following.
Duty deferment approval has to be obtained from HMRC who will issue a Deferment Approval Number (DAN) to approved entities. Under the Union Customs Code (UCC) a duty deferment facility must also be backed by a “Comprehensive Customs Guarantee” (CCG) of twice the maximum monthly payment.  This reflects the fact that, by the time payment is taken, half of the following month has also elapsed when it is expected that goods will continue to arrive or be removed thus becoming subject to a customs duty charge or “customs debt”.
Deferred duty charges can be taken by HMRC only from a UK Bank account.