The short answer
A three-bill comparison reveals expiring discounts, new fees, insurance changes, and forgotten connected-device lines.
Step by step
Compare the current bill with bills from one and three months earlier, focusing on each line rather than only the total.
Mark every changed base-plan price, tax, fee, insurance charge, device credit, and third-party purchase.
Check whether autopay, paperless, employer, military, senior, or loyalty discounts still appear.
Remove unused features and ask for the carrier's current lower-cost plan options without changing device credits unexpectedly.
Document the change and verify it on the next bill.
Before you finish
Keep screenshots, receipts, chat transcripts, confirmation numbers, and the first bill after a change. Carrier terms and account eligibility can change, so verify the final price and conditions directly before submitting an order.