Bad debt expense is the cost to a company resulting from credit sales that are uncollectible. It represents an estimation of accounts receivable that will not be collected.
Accounts Receivable: Money owed to a company by its customers for goods or services sold on credit.
Allowance for Doubtful Accounts: A contra-asset account used to estimate the portion of accounts receivable that may not be collectible.
Trade Credit: The extension of credit by a seller to allow the buyer to pay for goods or services at a later date.