CAF number applications and authorizations

by | Sep 12, 2025 | Technology & Process Questions

Here’s what HIVE AI had to say about “CAF number applications and authorizations”:

CAF number applications and authorizations

What a CAF number is and when you get one

  • A Centralized Authorization File (CAF) number is a unique nine-digit ID assigned the first time you file a third‑party authorization (Form 2848 POA or Form 8821 TIA) with the IRS; the IRS mails a letter with your assigned CAF number. Use the same CAF on all future authorizations. 1

How authorizations are submitted and recorded

  • Taxpayers submit Form 2848 (POA) or Form 8821 (TIA) to the CAF Unit by mail or fax per the form instructions; the authorization must post to the CAF database before practitioners can use Transcript Delivery System (TDS) via e‑Services for that client. 2
  • If any IRS office receives a 2848/8821 instead of the CAF Unit, they must fax it to CAF within 24 hours. CAF addresses and fax numbers include Memphis and Ogden; see IRS’s state mapping for where to file. 3
  • The CAF system records information from both POAs and TIAs so IRS personnel can verify who is authorized, what acts are authorized, and to send copies of notices where applicable. A CAF number is generally issued to a recognized representative (POA) or an appointee (TIA). Only authorizations that meet CAF criteria (including specific tax periods) are recorded. 4

Submitting and tracking through Tax Pro Account

  • Tax Pro Account processes real‑time POA/TIA requests for individuals and shows your request history. Approved requests display immediately; if a taxpayer rejects or processing fails, no status is shown. 5
  • You can link your CAF to Tax Pro Account by requesting a mailed PIN to the CAF address of record; after linking, you can view your entire client list from CAF and withdraw from authorizations. Only the requester can use the PIN. This visibility includes IMF and BMF authorizations, regardless of how they were submitted. 6

Processing timeframes and availability

  • CAF receipts are processed first‑in, first‑out; typical time is within about 5 business days for CAF‑input items. OTIA/return designations have different timelines; POAs and TIAs recorded on CAF are available via Master File/IDRS CFINK. 7

Using CFINK to verify authorizations

  • IRS employees can use IDRS command codes to verify authorizations. CFINKT lists the authorizations for a specified taxpayer when the TIN and the representative’s CAF number are input; errors indicate invalid TINs, missing/invalid CAF numbers, no authorizations, or database availability issues. 8

Getting, losing, or merging CAF numbers

  • If a practitioner doesn’t yet have a CAF number, one is issued automatically with the first recorded submission to CAF. If multiple CAF numbers exist in error, the CAF Function can merge or correct records per IRM procedures; lost/forgotten CAF inquiries are handled by CAF via Letter 1727C. 7
  • Internal CAF assignment rules caution that CAF numbers are system‑generated (prefix “03”); errors like “CAF NUMBER ALREADY EXISTS” occur if attempting to change to an existing number. CAF can also send Letter 1727C to inform a third party if a number was assigned in error. 3

Practical tips for authorizations

Preparing Forms 2848 and 8821

  • Use Form 2848 to authorize representation before the IRS for specific forms/periods and Form 8821 to authorize inspection/receipt of confidential tax information; follow “Where to File” charts and state mapping to send to the correct CAF Unit. 2
  • The IRS records POAs and TIAs on CAF; if you need help on completing these forms in specialized areas (e.g., tax‑advantaged bonds), contact the IRS agent/specialist who requested them. 9

Using Tax Pro Account vs. uploading forms

  • For individuals, Tax Pro Account is fastest (real‑time). It also allows viewing active CAF authorizations and withdrawing in real time once you’ve linked your CAF. For corrections beyond same‑day re‑requests, use the “Submit Forms 2848 and 8821 online” option. 5

Notices and additional acts

  • The CAF system supports recording “additional acts” from Form 2848 line 5a; be precise about which authorized representative each additional act applies to. 1

CAF unit contact references

  • CAF Unit addresses, fax numbers, and state mapping are posted publicly; use the mapping to route your submissions to the correct site (Memphis, Ogden, and Philadelphia). 3

Common issues and resolutions

  • TDS rejects due to missing/unposted authorization: verify that the POA/TIA has posted to CAF for the correct tax periods before attempting TDS; EPSS guidance directs such support to confirm the CAF number only for TDS rejects and refer other requests to PPS/CAF. 2
  • Can’t see clients in Tax Pro Account: ensure your CAF is linked using the mailed PIN to the CAF address; only the requester can use that PIN. 6

If you share your scenario (new practitioner needing a CAF, merging duplicates, or a TDS reject), I can outline the exact steps and addresses/fax numbers to use.

Sources

1 – IRS.gov – The Centralized Authorization File (CAF) – Authorization rules 📄 Summarize
2 – IRS IRM 3.42.8 E-Services Procedures for Electronic Products and Services Support (EPSS) 📄 Summarize
3 – IRS IRM 21.3.7 Processing Third-Party Authorizations onto the Centralized Authorization File (CAF) 📄 Summarize
4 – Treasury Regulation 601.506 📄 Summarize
5 – IRS.gov – Tax Pro Account 📄 Summarize
6 – IRS IRM 21.2.1 Systems 📄 Summarize
7 – IRS – Publication 4019 Third Party Authorization, Levels of Authority 📄 Summarize
8 – IRS IRM 2.3.31 Command Codes CFINK , RPINK, KAFFQ and KAFTQ for CAF Inquiry 📄 Summarize
9 – IRS.gov – Forms 2848 and 8821 for tax-advantaged bonds 📄 Summarize

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