9. A non-transitory computer readable storage medium storing one or more programs for execution by one or more processors of a portable electronic device, the one or more programs including instructions for: displaying a user interface that includes an area for receiving an account identifier identifying an account of an account holder, wherein the account identifier includes multiple sets of characters that do not overlap with one another; displaying a first set of candidates for a first set of characters of the multiple sets of characters, each candidate in the first set of candidates comprising a plurality of characters; detecting a selection, by a user of the electronic device, of a first candidate of the first set of candidates for the first set of characters; in response to detecting the selection of the first candidate of the first set of candidates for the first set of characters, displaying characters in the first candidate in the area for receiving an account identifier; subsequent to detecting the selection of the first candidate of the first set of candidates for the first set of characters, determining a current geographical location of the electronic device; displaying a second set of candidates for a second set of characters of the multiple sets of characters, each candidate in the second set of candidates comprising a plurality of characters and corresponding to a respective geographical location selected based on the current geographical location of the electronic device, wherein the candidates in the second set of candidates are ranked according to their respective distances from the determined current geographical location and displayed according to the ranking; detecting a selection by the user of a second candidate of the second set of candidates for the second set of characters; in response to detecting the selection of the second candidate of the second set of candidates for the second set of characters, displaying characters in the second candidate in the area for receiving an account identifier adjacent to display of characters in the first candidate in the area for receiving an account identifier; subsequent to detecting the selection of the second candidate of the second set of candidates for the second set of characters, determining that the electronic device has received user input for all but a last set of characters; in accordance with a determination that the electronic device has received user input for all but the last set of characters: ceasing to display candidates for any set of characters of the multiple sets of characters so as to require manual entry of the last set of characters, wherein the last set of characters comprises a plurality of characters; receiving manual entry of each respective character in the last set of characters; and displaying, in the area for receiving an account identifier, manually entered characters in the last set of characters; subsequent to receiving manual entry of each respective character in the last set of characters, receiving, from the user, a confirmation instruction; and in response to receiving the confirmation instruction, sending a request to perform a transaction using the account identified by the account identifier to an account management system that manages the account, wherein the request includes the account identifier and individual information of the user, and wherein the account management system is configured to authenticate the transaction in accordance with a determination that the individual information matches information of the account holder.
10. The computer readable storage medium of claim 9 , wherein the one or more programs include instructions for: prior to detecting the selection of the first candidate of the first set of candidates: receiving a manual input of one or more characters; and replacing the display of the first set of candidates with a subset of the first set of candidates, wherein candidates in the subset correspond to the one or more characters.