How to send tax documents securely: an ultimate guide

Sending tax documents might seem simple, but doing it securely is anything but. With cyber risks growing and client expectations rising, the way you handle sensitive information matters more than ever.

In this article, we’ll walk through what it really takes to protect client data at every step. You’ll learn smarter methods for sending and managing sensitive files, uncover common mistakes accountants make (and how to spot them with a quick self-check quiz), and get practical answers to client questions about secure document exchange.

Why securely sending documents matters more than ever

Tax documents hold a detailed snapshot of your clients’ financial lives — and in the wrong hands, they become a powerful weapon. And now more than ever, the risks are real.

According to the Identity Theft Resource Center’s 2024 report, the financial services sector experienced 737 data compromises last year, leading to nearly 48 million victim notices — making it the most compromised industry for the first time since 2018.

When tax records aren’t properly secured, hackers and scammers have everything they need to commit serious crimes. Here’s what’s at stake:

• Identity theft: Using stolen personal details to commit fraud or open new accounts.
• Tax fraud: Filing fake tax returns under someone else’s name to steal refunds.
• Financial theft: Accessing bank accounts or credit lines to siphon funds.
• Unauthorized accounts: Opening payday loans, utility accounts, or credit cards without permission.
• Medical identity theft: Receiving healthcare services billed to a stolen identity.
• Criminal impersonation: Giving someone else’s name during arrests, leading to wrongful criminal records.

Every unprotected document is a door left ajar. That’s why safeguarding your clients starts with one priority: sending sensitive documents securely, every time.

Quick check: How safe are your habits for sending documents?

Before we dive deeper, here’s a quick self-check. It’s not about what tools you use — it’s about how you make everyday decisions when client data is involved.

Is it safe to email tax documents?

Emailing tax documents might seem convenient, but it’s far from the safest choice. Standard email lacks end-to-end encryption, making sensitive information vulnerable to interception, phishing attacks, and unauthorized access.

So even when handled carefully, email simply doesn’t offer the level of protection today’s cybersecurity landscape demands.

Recognizing these risks, the IRS only allows emailing tax documents in very specific cases — and only if a few strict rules are met. You can send documents via email to an IRS employee if:

• You’re already working with them on an ongoing issue like an audit or appeal.
• You’ve verified your identity and agreed to use encrypted email.
• You encrypt any attachments and share passwords by phone — not in the email.
• You keep sensitive info (like SSNs) out of subject lines and message text.

Unless these boxes are checked, the IRS — and cybersecurity experts — recommend using safer ways to send documents.

Proven methods to send documents safely

Here are three proven methods for securely sending documents without exposing your clients — or your firm — to unnecessary risks.

1. Encrypted email

Some popular email providers, like Outlook and Gmail, offer basic encryption features to help protect sensitive documents. When you enable encryption, your emails are scrambled so that only the person who is supposed to read them can decipher them.

For even stronger security, you can add encryption plug-ins like Preveil. These tools build on your existing email service by encrypting messages directly on your device — ensuring that even email servers don’t have access to the content.

However, even with these extra layers, emailing tax documents isn’t completely foolproof. Encryption typically protects the body of the email and attachments, but subject lines and some metadata often remain exposed. A small mistake — like mentioning a client’s name or Social Security number in an unprotected field — can still create serious risks.

To sum up: If you must use email to send tax documents, make sure to double-check your settings, avoid including sensitive information in subject lines, and verify recipient addresses before hitting send.

2. Secure file-sharing services

For one-off document transfers, secure file-sharing platforms offer a much safer option than regular email. Services like OneDrive, Dropbox, and ShareFile allow you to upload documents, apply password protection, control who can view or edit files, and monitor access.

Government options, like the IRS Document Upload Tool, also provide secure file transfer for specific interactions with the IRS. This tool lets taxpayers and tax professionals upload documents directly to IRS.gov instead of mailing physical copies.

In short, secure file-sharing tools are fine for occasional use — but keeping everything locked down takes constant oversight, and that overhead only grows as your firm scales.

3. Secure online platforms

For firms managing sensitive client data day in and day out, relying on isolated file-sharing tools isn’t enough. That’s where secure practice management platforms — like TaxDome — can make a real difference.

TaxDome protects the entire client journey. Every file upload, e-signature, payment, message, and process happens inside a centralized, encrypted environment designed specifically for accountants, bookkeepers, and tax professionals.

Here’s what that means in practice:

• Controlled access: You decide exactly who can view, edit, or manage files, both internally and externally.
• Encryption everywhere: iles and communications are protected by 256-bit encryption and SSL — in transit and at rest.
• Authentication made simple: Two-factor authentication (2FA), optional Google SSO, and biometric login on mobile create secure yet easy access points for both staff and clients.
• Complete visibility: Every action — every login, upload, signature — is tracked with detailed audit trails, helping firms meet rising client expectations for transparency.

With TaxDome, you can manage everything in one secure platform, purpose-built to protect your firm’s reputation and your clients’ trust.

Best practices for secure document exchange

No matter which method you choose to send documents, following a few core security practices makes a major difference.

1. Prepare documents carefully before sending

Before uploading or sending anything, take a few simple steps to avoid confusion and mistakes:

• Use clear, descriptive file names (e.g., “2024_ClientName_TaxReturns.pdf”).
• Organize documents into folders by tax year, client, or form type.
• Scan physical documents with high-quality settings for better digital copies.
• Clean up old drafts or duplicate files to reduce the risk of sending outdated information.

A little preparation upfront makes secure delivery — and later retrieval — much easier.

2. Verify recipient details

Always double-check who you’re sending documents to:

• Confirm email addresses or client portal usernames are accurate and current.
• If sending via email, verify the full address and recipient’s name.
• For online transfers, make sure the recipient’s account is active and ready to accept files.

Even small mistakes can put confidential data in the wrong hands.

3. Use strong, unique passwords

Strong passwords are still your first line of defense against data breaches and unauthorized access:

• Choose passwords that are 12–14 characters long and include a mix of letters, numbers, and special symbols to keep them hard to crack.
• Avoid anything predictable, like birthdays or simple words.
• Use a password manager to generate and store credentials securely.
• Never reuse passwords across multiple accounts.

One weak password can undermine even the best security setup.

4. Enable multi-factor authentication (MFA)

Even strong passwords aren’t enough on their own. MFA adds a critical second layer of protection by requiring an extra verification step:

• Use authenticator apps, SMS codes, biometrics (like fingerprint or Face ID), or security keys.
• Enable MFA on email accounts, client portals, cloud storage, and any system involved in tax document handling.

MFA can stop hackers in their tracks, even if they manage to steal a password.

5. Watch for phishing attempts

Phishing attacks are getting more sophisticated but the signs are still recognizable:

• Look for suspicious sender addresses, odd URLs, typos, or strange branding.
• Be cautious with emails requesting sensitive information or pushing for immediate action.
• If something feels off, call the organization directly using a verified phone number — never trust the contact information in a suspicious message.

Staying vigilant can prevent costly breaches and client trust issues.

Mistakes that could put client data at risk

Even with the best intentions, small mistakes can open big security gaps. Here are a few risks to steer clear of when handling sensitive data:

• Sending physical mail without tracking: Always use certified mail or a courier service that provides delivery confirmation.
• Sharing tax information over SMS or public Wi-Fi: Text messages and open networks are easy targets for hackers. 
• Emailing unencrypted attachments: If you must use email, encrypt both the message and any files — and double-check that no sensitive information leaks into the subject line.
• Relying on unverified third-party services: Free or unfamiliar apps may lack essential security protections. Always vet platforms before trusting them with client data.
• Skipping security updates: Ignoring software or system updates leaves known vulnerabilities open. Update all apps, antivirus programs, and operating systems regularly.
• Sharing passwords carelessly: Never send passwords via email or text. Use phone calls or secure password-sharing tools to pass along credentials safely.

Questions to ask yourself before sending a tax document

If you’re working with an accountant — or helping your own clients feel more confident — knowing the safest ways to send and manage documents matters. 

Is it safe to email my tax documents?

When sending sensitive information, standard email is not completely secure. Even with encryption, subject lines and some metadata can be exposed. If your accountant offers a secure portal or file upload system, always use that instead of traditional email.

What’s the best way to send tax documents to an accountant?

The safest way to send documents is through a secure client portal designed for financial data handling, like TaxDome. These platforms use encryption, access controls, and authentication features to protect files at every step. 

What should I do if I accidentally send documents to the wrong email address?

First, notify your accountant immediately and explain what was sent and where. If possible, contact the unintended recipient and request deletion without opening the file. Going forward, always double-check recipient details before sending, and use platforms that allow secure, permission-based access rather than open file sharing.

Can I use cloud storage (like Dropbox or OneDrive) to send tax documents?

Cloud storage can be a safer option than regular email if you use encrypted links, strong passwords, and limited access permissions. However, for ongoing document exchanges and communication, it’s better to use a secure platform designed specifically for accounting firms.

How can I tell if my accountant is handling my information securely?

Look for signs like the use of a secure client portal, multi-factor authentication (MFA) requirements, clear communication about data handling, and transparency about document access policies. It’s also a positive sign if your accountant explains security protocols openly and welcomes your questions.

Final thoughts

Handling tax documents securely is about protecting trust at every step. Every decision, from the tools you choose to the habits you build, plays a part in safeguarding sensitive information.

By being intentional with how you send, store, and manage tax documents, you don’t just lower the risk of breaches. You build stronger client relationships, protect your firm’s reputation, and prove that security is part of the service you deliver.