Cheque writers are advised to specify the amount of the cheque before signing it. A blank cheque can be extremely expensive for the drawer who writes the cheque, because whoever obtains the cheque could write in any amount of money, and might be able to cash it (if the current account (US: checking account) contains sufficient funds, and depending on the laws in the specific country). Under American law, a blank cheque is an example of an “incomplete instrument” as defined in the Uniform Commercial Code’s Article 3, Section 115 (a). Writing an amount in a blank cheque, without the authority of the signer, is an “alteration”. It is legally equivalent to changing the numbers on a completed (non-blank) cheque.