Bas Bleu, an online bookseller, was among the businesses that recently appeared to confirm the city of Sandy Springs’ concern that an incorrect sales tax—Atlanta’s 8 percent instead of the Sandy Springs area’s 7 percent–is sometimes applied to local purchases due to software confusion. Bas Bleu now says it charges the correct tax, but that software indeed confused the issue by showing customers an 8 percent estimate.

Bas Bleu, which is Atlanta-based, said it uses two different systems to calculate the estimated tax and to charge the actual tax. The company said it has changed its purchase form to clarify the 8 percent is an estimate.