Send a fax

IRS CP259 and CP518B

Fax your CP259 reply to the IRS

The IRS shows a business return it hasn’t received. Reply at the fax number its page gives, which takes CP518B replies too.

IRS fax number

To

CP259 and CP518B replies

Fax

+1 855 800 5944

$4.99 for up to 10 pages. Nothing if it fails.

Send to this number

From the IRS’s Understanding your CP259 Notice, reviewed Aug 11, 2026, last checked Oct 31, 2026. The IRS asks you to understand a fax service’s privacy and security policies: read XipFax’s Privacy Policy.

What the office requires

  • What to send

    The IRS’s page on CP259 says what your reply needs. Read it on IRS.gov

  • Include the Response form

    Use the Response form that came with your notice.

Pricing

Pay per fax. Or get your own number.

One fax

$4.99

for up to 10 pages, then 20¢ a page

  • No subscription.
  • A fax that fails costs nothing.
  • An email confirms each fax, delivered or failed.
  • A confirmation to download as proof of delivery.
Send a fax

If a fax failsA fax that fails costs nothing: we don’t charge for it, or we refund what you paid. Other charges, plan fees included, aren’t refunded unless the law requires it.

The plan

$14.99a month

for your own number and 300 pages a month

  • Your own fax number, in a US area code you choose.
  • 300 pages a month, sent and received, then 5¢ a page.
  • Received faxes in your log, and by email as a PDF.
  • Faxes you send draw on your pages, with no payment each time.
  • Cancel online any time.
Get your number

Your plan renews automatically every month until you cancel it. You pay $14.99 today, and $14.99 on the same date each month after that. Cancel any time before your next renewal date and you won’t be charged again: choose Cancel plan on Your number in XipFax. Your plan then runs to the end of the month you paid for, and your number is yours until then.

Faxes go to US and Canadian fax numbers. Prices are in US dollars.

How it works

  1. 1

    Choose who it’s to.

    Find an office on XipFax, like the IRS’s CAF unit for Form 2848, or type any US or Canadian fax number.

  2. 2

    Add your pages.

    Upload PDFs or photos. Put them in order, add a cover page if you like, and check every page in black and white, the way the office will receive it.

  3. 3

    Pay and send.

    Add your email for the confirmation, pay $4.99, and send. We email you when it’s delivered.

All the IRS forms and notices XipFax finds numbers for