The Oak Harbor, Washington, general sales tax rate is 6.5%. The sales tax rate is always 8.7% Every 2017 combined rates mentioned above are the results of Washington state rate (6.5%), the county rate (0% to 2.2%), the Oak Harbor tax rate (0% to 2.2%). There is no special rate for Oak Harbor. The Oak Harbor's tax rate may change depending of the type of purchase. Please refer to the Washington website for more sales taxes information. Oak Harbor city rate(s) 8.7% is the smallest possible tax rate (98277, Oak Harbor, Washington) The average combined rate of every zip code in Oak Harbor, Washington is 8.7%. Other 2017 sales tax fact for Oak Harbor