IBAN numbers and SWIFT codes will be essential for all payments and receipts from February 2014

This includes payments made to or to be received from accounts within the same country – no longer just from abroad.

In Spain, IBAN numbers start with the letters ES, whilst in the United Kingdom they start with GB, and are followed by two numbers, which identify which bank the account is held in.

An IBAN number can then only be used with a SWIFT code, sometimes known as a BIC code, which is a series of letters and numbers unique to each bank.

It usually includes the first four letters of the bank name – BARC for Barclay's, for example, or CAIX for La Caixa – with eight other digits, mainly letters and often including Xs and zeroes.

Spanish bank account numbers have 20 digits – the first four being the bank itself, the next four denoting the branch, another two being the security code unique to the individual customer's account, and finally, a 10-digit account number.

This differs from UK bank account numbers which are eight digits long but have a six-digit 'sort code', separated by dashes into three numbers of two figures each and which shows the branch of the bank involved.

In other words, for a Spanish account number which reads 0123 4567 89 0009876543, the 0123 is the name of the high-street bank, the 4567 is the branch where the original account was set up or has since been transferred to, the 89 is the control digit and the remainder is the actual account.

But from February, the IBAN number will be needed – if this, for the bank in question, is ES21, the full number needed to pay a transfer in or to receive money transferred from elsewhere is ES21 0123 4567 89 0009876543.

Anyone who has money regularly paid into their bank accounts in the form of wages, invoices settled by clients, standing orders from an account or savings plan in the UK, or a pension will have to let the sender know what their IBAN code is.

The Department of Health and Social Security (DHSS) in Newcastle-upon-Tyne, UK, is contacting all State pensioners asking them to confirm their full account numbers and IBAN codes.

This is imperative, since otherwise pension payments will stop until the details are indeed confirmed, as the DHSS will not be able to send them through.

Obtaining IBAN and SWIFT or BIC codes for accounts merely involves a visit or, in some cases, a telephone call to the bank in question, but they will not normally give these to anyone other than the account-holder.

Banks do not charge for giving IBAN and SWIFT codes or for changing direct debits or standing orders to reflect these, an attempting to do so is illegal and should be reported.

The move comes as a result of European Directive 260/2012, known as the Single Euro Payments Area (SEPA) and is designed to facilitate the process of transfers, direct debits and standing orders between member States.

It applies to 33 countries – the 28 members of the European Union, plus Iceland, Norway, Switzerland, Liechtenstein and Monaco.

The advantages are that payments made by bank transfer are much safer, since one can instantly see which country the money is coming from or going to, and the BIC or SWIFT and IBAN for the bank itself will have to tie up with the account number, meaning there is far less danger of accidentally paying money into the wrong account by reversing or changing a digit in error.

According to the Bank of Spain, only 0.24 per cent of payments made to and from accounts in the country are effected using an IBAN and SWIFT.