From the Washington Department of Revenue:
Scammers posing as Washington Department of Revenue employees are again calling Washington businesses to direct them to a bogus international phone number that charges them for the call, the Department warned today.
The automated phone calls state that the Department of Revenue has been trying to reach the business about its tax account, and to call 1-800-631-4228. When the taxpayer calls that number, another recording prompts them to call 10-15-15-8000. If the business calls that number, approximately $7 will be charged to its telephone account.
The Department does make phone calls to businesses that fall behind on filing their state excise tax returns, and leaves a nearly identical callback number of 1-800-631-4028. Anyone calling that number will not be directed to call a second number that charges a fee. The Department also operates a toll-free telephone assistance number, 1-800-647-7706.
This same scam occurred exactly two years ago, but efforts to track down the perpetrators were unsuccessful because they were based in foreign countries.