Open your Access form in design view. Right-click on the object that you wish to change the tax order. In this example, it's the text box called SupplierID.
When the properties window appear, click on the button (with the three dots) to the right of the Tab Index property.
A "Tab Order" window will appear. Select a row and drag it to the appropriate tab order position. When you have finished setting the tab order, click on the OK button.