Regulating digital currencies, winding up the cheque system, more efficient handling of direct debits and system reliability will be key issues in the Reserve Bank's review of the retail payments system.On Friday, the RBA released an issues paper that will form the basis of consultation for the review, which will run over the coming year. It will look at regulations, such as the interchange rules, and also whether there are any gaps in the payments system that need to be addressed.Recent developments highlighted in the issues paper include the introduction of digital wallets and the growth of buy now pay later services. The RBA notes that such innovations rely on existing payments infrastructure.The review will also cover the international regulatory response to digital currencies.The issues paper makes several references to delays in the rollout of the New Payments Platform, though NPP volumes are now growing strongly. It will consider "any challenges posed by the various domestic schemes and frameworks and any changes or consolidation that might be worth considering".The RBA wants to look at the future role of cash, noting that in parts of Europe, such as Sweden, cash is now in decline. Public policy issues that might arise include maintaining adequate access to cash in the event of a significant contraction in the ATM network.The paper says may be appropriate for the industry to wind up the cheque system at some point.The RBA will address the handling of direct debits. It says: "Cancellation or redirection of direct debit and other automated payment arrangements is not always straightforward."It will also look at the reliability and resilience of the system, which is more critical given the declining use of cash.It wants to consider possible issuance of "an electronic form of banknotes" - an eAUD.