A PTIN identifies the individual who prepares a return for compensation. An EFIN identifies the firm authorized to submit returns electronically. An ETIN identifies whoever actually transmits the data to the IRS — almost always your software vendor, not you. Most tax professionals need a PTIN and an EFIN; very few need an ETIN.
The three get confused constantly, and the confusion is expensive: preparing returns without a PTIN, e-filing without your own EFIN, or sharing an EFIN across firms all carry real consequences.
The three identifiers at a glance
| PTIN | EFIN | ETIN | |
|---|---|---|---|
| Identifies | An individual preparer | A firm or office | A transmitter or software developer |
| Required if | You prepare or assist in preparing federal returns for compensation | Your firm originates e-filed returns | You send return data directly to the IRS |
| Format | P followed by 8 digits | 6 digits | 5 digits |
| Cost | Annual fee (roughly $20 — confirm current) | Free | Free |
| Renewal | Every calendar year | None, but keep the application current | None, but keep current |
| Background check | No suitability check | Yes — suitability required | Via the same e-file application |
| How to get it | IRS Tax Professional PTIN System, or Form W-12 | e-file application via e-Services | e-file application, selecting Transmitter or Software Developer |
PTIN — Preparer Tax Identification Number
Anyone who prepares, or substantially assists in preparing, a federal tax return for compensation must have a valid PTIN and include it on every return they sign. It belongs to the person, not the firm, and it follows you when you change jobs.
- Renewal is annual. PTINs expire on December 31. Renewal typically opens in mid-October. A lapsed PTIN during filing season is a common and avoidable problem.
- There is a modest fee. It has changed several times; check the current amount in the PTIN system rather than assuming.
- No suitability check. Unlike an EFIN, getting a PTIN does not involve a credit check or criminal background investigation, though you must certify your own tax compliance.
- Unenrolled preparers included. You do not need to be a CPA, attorney, or enrolled agent to hold a PTIN — but your representation rights before the IRS differ significantly depending on your credential.
Preparing returns for compensation without a valid PTIN can trigger penalties under §6695 and Circular 230 exposure.
EFIN — Electronic Filing Identification Number
The EFIN identifies your firm as an Authorized IRS e-file Provider. You apply through the e-file application in IRS e-Services, and the process is materially heavier than a PTIN:
- Create an IRS account and complete identity verification.
- Submit the e-file application as a firm, listing each Principal and Responsible Official.
- Fingerprinting for each Principal and Responsible Official — waived if the person is an attorney, CPA, or enrolled agent. The IRS provides a scheduling link after submission.
- Suitability check covering tax compliance, criminal background, credit history, and prior e-file compliance for the firm and each Principal and Responsible Official.
- Approval and EFIN issuance. Plan for roughly 45 days or more; apply well before filing season.
Rules that catch firms out
- An EFIN cannot be shared, sold, transferred, or borrowed. Each firm needs its own. Letting another practice file under your EFIN puts your entire e-file authorization at risk.
- EFINs are tied to a location. Additional offices generally require the application to reflect them. Moving requires updating the application.
- Monitor your EFIN return count. e-Services reports how many returns were filed under your EFIN. Checking it periodically during the season is the fastest way to detect that someone else is using it.
- Keep the application current. Changes in address, Principals, Responsible Officials, or firm structure must be reported. Stale applications cause problems at renewal.
- It can be suspended or revoked. Due diligence failures, security incidents, and e-file rule violations all put it at risk — which for an e-filing practice is an existential outcome.
ETIN — Electronic Transmitter Identification Number
The ETIN identifies the party that actually transmits return data to the IRS. If your firm prepares returns and clicks "e-file" inside commercial tax software, your vendor is the transmitter and uses their ETIN. You do not need one.
You need an ETIN only if you are building or operating the transmission pipeline yourself — selecting Transmitter or Software Developer on the e-file application. Two details are worth knowing if you ever go down that road:
- Selecting Software Developer yields a Software Developer ETIN that remains permanently in the test environment, alongside a separate Transmitter ETIN for production.
- A Transmitter ETIN does not automatically move to production after testing. It must be promoted, which requires contacting the IRS e-Help Desk.
Direct transmission also requires passing Assurance Testing (ATS), a separate communications test, and — for the Application-to-Application channel — an X.509 certificate and an Application System ID (ASID), which is your EFIN plus a two-digit sequence number.
Other identifiers you may encounter
| Identifier | Purpose |
|---|---|
| CAF number | Centralized Authorization File number, assigned when you first file a Form 2848 power of attorney or Form 8821. Identifies you in the IRS third-party authorization system. |
| EIN | Your firm's Employer Identification Number. Required on the e-file application — the application is filed by a firm, not a person. |
| ASID | Application System ID for Application-to-Application transmission. Derived from the EFIN. |
| Software ID | Issued per software package to Software Developers; required in the return XML. |
Which do you actually need?
- Employee preparer at a firm: PTIN only. The firm holds the EFIN.
- Sole practitioner who e-files: PTIN and EFIN.
- Multi-office firm: PTIN per preparer, plus EFIN coverage reflecting your locations.
- Preparer who only does paper returns for compensation: PTIN. An EFIN is required once you e-file, and the e-file mandate applies to most preparers filing more than ten covered returns per year.
- Software company or direct transmitter: PTIN if preparing, EFIN, and ETIN.
Frequently asked questions
Do I need my own EFIN if I use Drake, Lacerte, or ProConnect?
Yes. Your firm is the Electronic Return Originator and needs its own EFIN, which goes into the return. Your software vendor acts as the transmitter using their ETIN. The two are separate roles filled by separate parties.
Can two firms share one EFIN?
No. EFINs are issued to a specific firm and may not be shared, rented, sold, or transferred. Doing so risks suspension of e-file privileges for everyone involved.
How long does it take to get an EFIN?
Plan for around 45 days or longer once the application is submitted, because the suitability check is the long pole. Fingerprinting adds time if no Principal holds a CPA, attorney, or EA credential. Apply well ahead of filing season.
Does my PTIN expire?
Yes, every December 31. Renewal generally opens in mid-October for the following year.
Do I need an ETIN to e-file client returns?
Almost certainly not. Commercial tax software transmits under the vendor's ETIN. You need one only if you transmit directly to the IRS yourself.
What happens if my EFIN is compromised?
Contact the IRS e-Help Desk immediately and report the incident. Monitor your EFIN return counts in e-Services during the season so you find out from your own monitoring rather than from a client whose refund was stolen.
Where XyloDocs fits
XyloDocs is an AI tax workflow platform for tax firms — multi-channel document intake, bilingual client communication, organized client and tax-year filing with a full audit trail, and export to Drake, Lacerte, and ProConnect Tax. It sits upstream of the identifiers above: your firm keeps its EFIN and your preparers keep their PTINs, and XyloDocs handles getting documents in and organized before they reach your tax software.
See the full feature set, or read our companion guides to IRS Pub 1345 Online Provider requirements and WISP requirements for tax firms.
Last verified: August 9, 2026 This article is general information about IRS tax professional identifiers, not legal advice. Fees, processing times, and requirements change — verify current details on irs.gov before acting.
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