CUP was initially concerned that overseas merchants might fail to recognise the new logo and refuse to accept new-style UnionPay cards. Therefore, for a period, unified domestic debit and renminbi (RMB) single currency credit cards used the new logo, while international debit cards and dual currency credit cards used the old logo. From the beginning of 2009, dual-currency credit card banks began to gradually introduce the use of the new UnionPay logo.[citation needed]