Quick principle
Use the official online or phone route first when it can solve the task. If you need in-person help, schedule the appointment and bring a complete file.
Read every page
Note the notice number, response date, proposed change and contact details. Compare the figures with the return and your records.
Respond through the stated channel
Some notices require no reply; others allow an online response, phone call or mailed documents. Follow the instructions printed on your notice.
Prepare for in-person help
If the issue remains unresolved, bring the complete notice, related return, proof supporting your position and records of prior calls or correspondence.