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CP518/618
CP518/618 — Final Notice - Return Delinquency
What this IRS notice code means, and what to check before you reply.
What to do next
Start with these steps before you reply.
CP518/618
Read the notice carefully and note any deadline. Gather returns, notices, and payment records. Book a free strategy session before responding if the amount is large, unclear, or collection language appears.
What the IRS language says
Final Notice - Return Delinquency
What it usually means
CP518/618 is in our IR Manual catalog. Official wording is dense — we translate it for business owners and individuals and map realistic next steps.
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