Each new vial of strips will come a coding strip. The coding strip has a number written on the top and that number should match the number on the side of your vial of strips. To code your meter to the vial of strips you have simply insert the coding strip when the meter is off. Wait for the code number to appear on the display. Remove the coding strip and the display will show "OK". That's it, you are done and ready to test. If you need additional directions regarding coding your meter check page 19 on your manual.