Under U.S. GAAP, you should be recognizing a reasonable portion of sales on account each period to bad debt expenses, with the contra entry to allowance for uncollectible accounts (a contra-revenue account). You estimate the amount in uncollectibles each period using some reasonable method, such as percent of outstanding receivables or aging of receivables. In your case, it sounds like you are treating them almost like a cash basis, directly writing them off when they occur. That is not compliant with U.S. GAAP unless you estimate that the uncollectibles are typically so small as to be immaterial.
Having allocated a portion of your receivables as uncollectible, when you recognize that a specific receivable is actually going to be uncollectible, you would then reduce the receivables by the uncollectible amount and similarly reduce the allowance for uncollectible accounts. For example:
On original sale (this would happen many times in the period, for various amounts):
DR Accounts Receivable $100
CR Sales Revenue $100
DR Cost of Goods Sold $80
CR Inventory $80
End of period (adjusting entry, based on your current estimation of how much of the receivables balance will be uncollectible):
DR Bad Debts Expense $2537
CR Allowance for Uncollectible Accounts $2537 (contra-asset to the Accounts Receivable balance)
In the period the original sale is determined to be uncollectible:
DR Allowance for Uncollectible Accounts $100
CR Accounts Receivable $100
