You or your agent hand it off. We mail it.
No printer, no envelopes, no stamps and no line at the post office. Five steps, and you only do the first one.
- 1YouYou upload the PDF
Sign up, log in, upload it, type the mailing address and pick the mail class. Or your agent sends it.
- 2WeWe print it
Every page, in the order you sent, in black and white or color.
- 3WeWe envelope and label it
We print the label and pay the postage: Certified Mail, or FedEx 2Day or Standard Overnight.
- 4WeWe take it to USPS or FedEx
Prepared for dispatch the next business day by our staff in Manhattan Beach, CA.
- 5WeYou get the proof
The tracking number, the mailing date, and photos of the pages, the sealed envelope and the receipt.
One page: Certified Mail $20.00, with a return receipt $24.00, First-Class $2.00. FedEx is priced by distance. You see the exact price before you pay.
Can someone else mail my tax forms for me?
Yes, when the form allows it: replies to IRS and state notices, 1099 and W-2 copies for recipients, Form 4868, payroll returns a corporate officer signs by stamp or software, and the paper-only forms the IRS lets you sign electronically. For federal forms sent Certified, or by FedEx 2Day or Standard Overnight, the mailing date is the filing date. Two limits: a paper Form 1040 or 1040-X needs your own handwritten signature, so e-file it or sign and mail it yourself, and we can't enclose a check, so pay online.
For people with a deadline and no time for the post office
The printing, the envelopes, the label, the postage and the trip to the post office, done accurately and on the record, with tracking numbers and fulfillment photos, for whoever has the deadline.
Accounting firms
An on-demand mailroom for client mail: notice replies, 1099 and W-2 copies in January, Form 941s for corporate clients, engagement letters and year-end packets. Each piece comes back with fulfillment photos, and a tracking number when the service has one, tagged with your client's ID.
Small businesses and LLCs
Payroll returns signed with an officer's stamp, elections such as Form 8832, the signed copy of Form 3115 that goes to the IRS on its own, and replies to state and city tax offices, without a trip to the post office.
Quarterly filers and sole proprietors
Estimated tax is paid online, so the voucher can stay home. We send the mail that's left: 1099-NEC copies for your contractors by January 31, Form 4868, and replies to IRS and state letters, each with the date it was mailed.
Late filers
E-file covers the current year and the two before it. An older return goes on paper with your own signature, so that one you mail yourself; we send the replies to the IRS letters about it, with the date on record.
TurboTax and e-file users
Your return went by e-file, but some paper still has to go: replies to IRS and state letters, Form 4868 when you'd rather mail it, the paper-only forms that accept a scanned signature, and 1099 copies for anyone you paid.
AI agents, IDEs and harnesses
Connect Claude, ChatGPT, your IDE or your agent harness over MCP or REST. The agent prices each piece with a dry run, you approve it, and the tracking number and fulfillment photos come back by webhook.
Federal tax forms people mail, and how each one is signed
Each card links the current form on irs.gov. The tag is the signature rule that decides whether a printed copy can go: the IRS accepts a scanned or electronic signature on paper only for the forms in IRM Exhibit 10.10.1-2, and the Form 941 and 940 instructions let corporate officers sign by stamp or software. We can mail the forms tagged in blue; the rest are here so you know what the IRS expects.
Returns, extensions and payments
E-file it if you can. A paper 1040 needs your handwritten signature, so sign it and mail it yourself, by Certified Mail.
Tax software can e-file amendments for recent years. A paper 1040-X needs your handwritten signature.
No signature line. Mail it by the due date, or skip it: a payment made online and marked as an extension payment extends the deadline.
Its vouchers travel with a check, and we can't enclose one. Pay each quarter online with IRS Direct Pay or EFTPS instead.
Only for a check sent with a return. Paying online replaces it.
Notices, claims and requests
Answer by the date on the notice, at the address on it. Many notices also take a fax or an online upload; by mail, send it Certified.
Due within the 30-day window your collection notice gives. Send it to the address on the notice.
Penalty and interest relief and some refund claims, mailed to the address in its instructions.
Most people can set up a plan online. On paper it goes with your return, or on its own to the address in the instructions.
Fax or mail it to your local Taxpayer Advocate office.
Traces a refund that never arrived. It is on the IRS list of paper forms that accept an electronic or scanned signature.
Mailed to the address in its instructions, signed by hand.
Submit it online with an electronic signature, or fax or mail it signed by hand.
Lets someone see your tax records. Online with an electronic signature, or by fax or mail signed by hand.
Business elections and changes
The election can take effect no more than 75 days before the date it is filed, so the mailing date matters.
Every shareholder signs. Fax it or mail it to the address in the instructions.
For an automatic change, the original goes with your return and a signed copy goes to the IRS separately.
When it is due depends on the kind of request; the instructions give the address.
Due within 60 days of a change in responsible party. Signed by hand.
Due within 30 days of the transfer. The IRS also takes it online; if you mail it, send it Certified and give a copy to your employer.
Payroll and information returns
Due the last day of the month after each quarter. Corporate officers or authorized agents may sign by rubber stamp, mechanical device or software.
Due January 31, or February 10 when every deposit was on time. The same stamp or software signature is allowed.
Employee copies B, C and 2 go out by January 31 and can be printed on plain paper. Copy A goes to the SSA, online if you file 10 or more.
Copy B to each contractor by January 31. A statement properly addressed and mailed by its due date counts as furnished on time.
Copy B by January 31, or by February 15 when boxes 8 or 10 are filled in.
Paper only below 10 returns, and only on the official red-ink forms the IRS scans. E-file Copy A through IRIS instead.
Estates, gifts and foreign trusts
Due nine months after the date of death. Form 4768 asks for more time.
Due April 15 of the year after the gift. Extending your Form 1040 extends it too.
Due with your income tax return, extensions included. Late-filing penalties are steep, so keep proof of the date.
Due March 15 for a calendar-year trust. Form 7004 extends it.
More time to file Form 706, or to pay the estate tax.
Tells the IRS who acts for an estate, a trust or a person. Signed by hand.
For the Form 6166 certificate a treaty country asks for.
Every other federal form and its instructions: IRS forms and instructions. Mailing addresses: where to file, and for FedEx the street addresses for delivery services.
State and city tax forms, and where they live
States and cities set their own forms, signature rules and timely-mailing rules, so read the instructions for the form you are sending. Each link opens the tax agency's own forms or income tax page.
No state tax on wages: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington and Wyoming. Washington does tax some capital gains.
City and local income taxes
City income tax is part of the New York State return, IT-201 or IT-203.
Wage, earnings, net profits and business taxes, filed with the city's Department of Revenue.
Local earned income tax goes to the collector for your municipality; the state's Act 32 page lists the codes and collectors.
City income tax goes to RITA, CCA or the city's own tax office. School district income tax is filed with the state on the SD 100.
Detroit and other Michigan cities levy an income tax; the state's City Tax page has their forms.
Each city levies an earnings tax and has its own return.
The Arts Tax and the Metro and Multnomah County income taxes are filed with the City of Portland's Revenue Division.
County income tax is figured on the state return.
Which USPS and FedEx services count as filed on time
For federal forms, section 7502 treats a form mailed by its due date as filed on time. The date comes from the USPS postmark, or from the record of an IRS-designated delivery service. States and cities have their own rules.
| Service | The date that counts | What you can show | One page |
|---|---|---|---|
| USPS Certified Mailcertified | The USPS postmark on the sender's receipt, when the clerk applies it. | Certified number, acceptance and delivery scans. One of the regulation's ways to show it was delivered. | $20.00 |
| Certified, return receiptcertified_return_receipt | As Certified Mail. | Adds the electronic return receipt: who signed for it, and when. | $24.00 |
| USPS Priority Mailpriority | The date on the postage; label postage counts if it arrives in the usual time. | USPS Tracking with the acceptance scan. Not evidence of delivery under the regulation. | $15.00 |
| USPS First-Class Mailfirst_class | The date on the postage; label postage counts if it arrives in the usual time. | Our dated photos and status events. No USPS tracking. | $2.00 |
| FedEx 2Dayfedex_2day | The date FedEx records: an IRS-designated delivery service. | FedEx tracking to delivery. Use the IRS street address, never a P.O. box. | By distance |
| FedEx Standard Overnightfedex_overnight | The date FedEx records: an IRS-designated delivery service. | FedEx tracking to delivery. Use the IRS street address, never a P.O. box. | By distance |
| FedEx Express Saverfedex_express | Not designated: the day the IRS receives it is the filing date. | FedEx tracking. | By distance |
| FedEx Groundfedex_ground | Not designated: the day the IRS receives it is the filing date. | FedEx tracking. | By distance |
Prices are for one black-and-white page at new-account rates; each extra page adds $0.40 plus any postage increase. FedEx is priced by distance from Manhattan Beach, CA. A dry run gives the exact price.
Pick the service for the deadline
- A federal due dateCertified Mail, with a return receipt when you want the signature. The mailing date is the filing date, so send it to us at least two business days early.
- You'd rather use FedExFedEx 2Day or Standard Overnight, addressed to the IRS street address for delivery services. Never Express Saver or Ground.
- "Must be received by"When the instructions count the day it arrives, a postmark doesn't help. Use FedEx Standard Overnight and send it early.
- Due todayToo late for us: we prepare mail for dispatch the next business day. Take it to a post office counter and ask for Certified Mail with a postmarked receipt.
A USPS postmark can show a later day than the day you mailed
Since December 24, 2025, the USPS Domestic Mail Manual (section 608.11, Postmarks and Postal Possession) says a machine postmark carries the date of the first automated processing, which can be a day or more after the envelope went into a collection box. USPS calls it a clarification of existing practice. Either way, a sorting machine shouldn't decide whether your form was on time.
Dates that don't depend on a sorting machine
- Certified Mail with the sender's receipt postmarked by the clerk: the regulation makes that postmark the filing date.
- A manual postmark, free on request at a retail counter.
- FedEx 2Day or Standard Overnight to an IRS street address: the date FedEx records counts.
- Postage printed by a label vendor carries its own date, which counts only if the envelope also arrives in the usual time.
We prepare tax mail for dispatch the next business day, hand it to USPS or FedEx, and photograph the receipt.
Tracking numbers and fulfillment photos for every piece
Staff at our facility in Manhattan Beach, CA print, pack and mail every piece, and each step leaves a record you and your agent can read.
| 01Before it prints | A dry run gives the exact price and a preview of the document. With approval on, nothing prints until you approve it. |
| 02Printed and packed | Photos of the printed pages and of the sealed envelope with its label. The mail.ready webhook carries them. |
| 03Matched | A photo of each prepared letter must match the order's own first page and postage label before it can be marked ready. |
| 04Handed over | A photo of the receipt, the date it was mailed, and the Certified or FedEx tracking number, in the mail.mailed webhook. |
| 05Delivered | The delivery scan, in the mail.delivered webhook. A return receipt adds the electronic record of who signed for it. |
| 06Kept private | Your file is encrypted at rest and deleted once the piece is mailed. Save the photos and tracking when they arrive: we keep only blurred previews of the photos. |
From your desk, or from your agent
- 01Sign up or log in, and add credits for postage and printing.
- 02Upload your PDF, type the mailing address from the form's instructions, and pick the mail class: Certified Mail, with or without a return receipt, or FedEx 2Day.
- 03Check the price and the preview, then send it. We take it from there, and you follow it with the tracking number and fulfillment photos.
TurboTax, H&R Block, TaxAct, FreeTaxUSA and TaxSlayer can all save a form as a PDF for mailing. Check its tag above first: a return you sign by hand goes from you.
# 1. Price it: nothing is created or charged
curl -X POST https://mailbox.bot/api/v1/mail \
-H "Authorization: Bearer $MAILBOX_AGENT_KEY" \
-H "X-Mailbox-MD-Version: $MAILBOX_MD_VERSION" \
-F "document=@form-941-2026-q3.pdf" \
-F "recipient_company=Internal Revenue Service" \
-F "recipient_line1=$IRS_STREET" \
-F "recipient_city=$IRS_CITY" \
-F "recipient_state=$IRS_STATE" \
-F "recipient_zip=$IRS_ZIP" \
-F "mail_class=certified_return_receipt" \
-F 'metadata={"form":"941","period":"2026-Q3","client":"c_1042"}' \
-F "dry_run=true"
# 2. Send the same request with requires_approval=true.
# It waits for your OK, then mail.ready, mail.mailed and
# mail.delivered arrive with the photos and tracking.Over MCP from Claude, ChatGPT, your IDE or your agent harness: get_mailbox_md, then send_outbound_mail with dry_run=true to show the person the price, then the same call with requires_approval=true, and get_outbound_mail for status and tracking. A sandbox key (sk_agent_test_) runs all of it for free.
Tax mail an agent can run, with a person signing off
Each piece goes through the same dry run, approval and proof as one sent by hand. An agent can't buy credits, and with approval on, nothing prints until you say so.
Notice in, reply out
An IRS or state letter reaches your mailbox address. A keyword rule on the sender flags it for the tax desk; the agent reads the page text, drafts the reply and prices it, and you approve it before it goes Certified.
January statements
Your books produce one PDF per contractor or employee. The agent sends each as its own letter by January 31, tagged with the form and recipient, and records the mailed date against each one.
Quarterly payroll
A corporation's Form 941, signed by an officer's stamp or software signature, goes Certified with a return receipt every quarter, with the period in its metadata so the proof files itself.
A deadline rule the agent keeps
Write the rule once in the agent's MAILBOX.md duties: Certified for filings, FedEx only as 2Day or Standard Overnight to the IRS street address, never Express Saver or Ground for anything with a due date.
## Tax filings - Federal filing with a due date: certified_return_receipt, two business days early. - FedEx only as fedex_2day or fedex_overnight, to the IRS street address for delivery services. - "Must be received by" deadlines: fedex_overnight. - Never fedex_express, fedex_ground, first_class or priority for a filing. - requires_approval=true on every filing, with the form, period and client in metadata.
A checklist for tax mail
- The right form for the right year: a prior-year return goes on that year's form.
- Signed the way the form allows. See the tags above.
- The address from the form's instructions or the IRS Where to File page. It depends on your state, the form and whether a payment goes with it.
- For FedEx, the IRS street address for private delivery services. FedEx can't deliver to a P.O. box.
- Every page and attachment in one PDF, in the order the instructions give.
- Payment made online. We can't enclose a check.
- A due date on a weekend or legal holiday moves to the next business day.
- Sent to us at least two business days before the due date.
- Your own copy kept: we delete the file after it is mailed.
What we don't do
- Preparing returns, or tax or legal advice, including which form to file.
- Signing for you, or making a printed copy count where the IRS wants your handwritten signature.
- Printing or enclosing checks.
- Copy A of Forms 1099 and W-2 on paper: that takes the official red-ink forms, or e-file.
- A return you can e-file: e-file is faster, and the IRS confirms that it arrived.
Tax filing mail, answered
Can someone else mail my tax return for me?
Yes, when the form allows it. We print, envelope, pay the postage on and mail the PDF you send, with photos of each step. A paper Form 1040 or 1040-X needs your own handwritten signature, so e-file it, or print, sign and mail it yourself by Certified Mail.
Does the postmark date still count as the filing date?
For federal forms, yes: section 7502 treats a form mailed by its due date as filed on time. With Certified Mail, the date is the USPS postmark on the sender's receipt. Since December 24, 2025, a machine postmark can show a later day than the day you mailed, so use Certified Mail or ask for a manual postmark at the counter.
Is Certified Mail proof that I filed?
Under Treasury Regulation 301.7502-1, Registered Mail, Certified Mail and the IRS-designated delivery services are the only ways, short of direct proof that it arrived, to establish that a document was delivered. A return receipt adds the signature of whoever signed for it.
Does FedEx count as on time for the IRS?
Only the designated services: FedEx First Overnight, Priority Overnight, Standard Overnight and 2Day, plus some international ones. FedEx Express Saver and FedEx Ground are not designated, so the day the IRS receives the envelope is the filing date. FedEx can't deliver to a P.O. box, so use the IRS street addresses for private delivery services.
Can I print my signature on a paper tax return?
Only on the paper forms the IRS lists in IRM Exhibit 10.10.1-2, such as Forms 706, 709, 3520, 3115, 8832 and section 83(b) elections, which accept a scanned or electronic signature. Form 941's instructions let corporate officers sign by rubber stamp, mechanical device or software. Other paper forms, Form 1040 among them, should carry your handwritten signature.
Can you mail 1099s and W-2s to my contractors and employees?
Yes. Send one PDF per person and we mail each as its own letter. A statement properly addressed and mailed by its due date counts as furnished on time: January 31 for Forms W-2 and 1099-NEC, February 15 for some others. Copy A for the IRS or SSA has to be e-filed or sent on the official red-ink forms.
Can you mail Form 941 every quarter?
Yes, for a corporation whose officer or authorized agent signs by stamp or software, as the Form 941 instructions allow. It is due the last day of the month after each quarter; send it Certified so the date is on record.
Do you include a check?
No. Pay with IRS Direct Pay, EFTPS or your state's online payment, and mail the form on its own where the instructions allow it.
Where should I mail it?
To the address in the form's instructions or on the IRS Where to File page; it depends on your state, the form and whether a payment goes with it. For FedEx, use the IRS street addresses for private delivery services. We mail to the address you enter, so check it against the instructions.
How soon does it go out?
We prepare it for dispatch the next business day. The filing date is the day USPS or FedEx takes it, so send it to us at least two business days before the due date.
Can I send you the PDF from TurboTax or H&R Block?
For forms that don't need a handwritten signature, yes: save the form as a PDF and send it here. The return itself is different. A paper Form 1040 needs your handwritten signature, so file it with the software's e-file, or print it, sign it and mail it yourself by Certified Mail.
Can an AI agent send tax mail for me?
Yes. The agent calls send_outbound_mail over MCP, or POST /v1/mail over REST, with dry_run=true for the exact price, then sends with requires_approval=true so you approve each piece. A sandbox key rehearses the whole flow for free and mails nothing.
Is my tax information safe?
Each file is encrypted at rest with AES-256-GCM under its own key, every read is logged, and the file you sent is deleted once the piece is mailed. Proof photos are kept only as previews with the lower half blurred. The trust center lists every control.
How much does it cost?
For one black-and-white page: Certified Mail $20.00, Certified with an electronic return receipt $24.00, Priority Mail $15.00, First-Class Mail $2.00. Each extra page adds $0.40 plus any postage increase. FedEx is priced by distance from our Manhattan Beach, CA facility. A dry run shows the exact price before you pay.
- 26 U.S.C. § 7502, timely mailing treated as timely filing and paying
- 26 CFR § 301.7502-1, postmarks, registered and certified mail, delivery services
- 26 U.S.C. § 7503, due dates on weekends and holidays
- IRS: designated private delivery services
- IRS: street addresses for private delivery services
- IRS: where to file paper tax returns, with or without a payment
- IRM 10.10.1 and Exhibit 10.10.1-2, electronic signatures on paper-only forms
- Instructions for Form 941, alternative signature method
- General Instructions for Certain Information Returns, statements to recipients
- USPS Domestic Mail Manual 608.11, Postmarks and Postal Possession
- Federal Register, Postmarks and Postal Possession (final rule, 24 November 2025)
- IRS: state government websites
Last checked against these sources on 27 October 2026.
Disclaimer. This page is general information, not tax, legal or accounting advice, and it doesn't replace a form's own instructions or a tax professional. Forms and rules change, so check them with the IRS or your state or city before you mail. mailbox.bot isn't affiliated with or endorsed by the IRS or any tax agency. Mail you send through us is covered by our Terms of Service.
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Mailed on time, with the proof to show it.
Send the PDF. Staff at our facility in Manhattan Beach, CA print it, mail it and photograph every step.