Calculation tools for Revenue offices
Verify Form 760 returns line by line, with every figure updated for the current tax year. Taxpayer information is never stored on Tabren servers.
Recalculates as you type. Nothing is written to disk.
Built for a security review
The three questions procurement always asks
Where does taxpayer data go?
Nowhere. Figures reach the calculation engine, are computed, and are discarded. Nothing is written to a database, a log or a file. What your staff type stays in their own browser until they clear it.
Who can reach it?
Your staff, on your terms. Sign in with the Microsoft 365 accounts they already have, or use a shared office license. Either can be limited to your own network, so the tool does not open elsewhere.
Can you prove who used it?
Yes. Every sign-in, source address and tool opened is recorded. The trail deliberately holds no figure from any return, so it evidences access without ever reconstructing a taxpayer's information.
Virginia Form 760
The whole return, not just the arithmetic
Built on a calculation engine already in daily use in a Commissioner of the Revenue's office, and rebuilt as a licensed service without changing a single figure it produces.
- Every line of Form 760, from federal AGI through to refund or amount due
- Age Deduction worksheet, including the income-based taper and the MFS split
- Credit for Low Income and Virginia EITC worksheet, with MFS allocation
- Spouse Tax Adjustment helper that computes the adjustment and applies it
- Handles the Age Deduction and Line 23 mutual exclusivity explicitly
- Recalculates as you type — no submit button, no page reloads
- Downloadable PDF report for the file, with preparer and reference fields
- Prior tax years stay available, because amended returns are real
Kept current
The annual update is the product
A spreadsheet is correct the year it was written. The failure that matters is not a wrong number that looks wrong — it is one nobody touched: the brackets get updated and last year's poverty guidelines quietly stay.
What that means on screen
- The tax year and its last update date are shown in the header, always
- No figure is duplicated between the engine and the page, so the two cannot disagree
- Next year's numbers are staged and reviewed before they go live
- Earlier years stay published, so an amended return uses the right figures
Access control
Two independent controls, not a choice between them
Offices routinely need both: staff signing in with their own work accounts, and access limited to the building.
Microsoft Entra ID single sign-on
Your staff use the Microsoft 365 accounts they already have, under your own MFA and conditional access policies. Setup is a single link sent to your IT department — no app registration or client secret for them to manage. Tabren can read a name and an email address and nothing else: no mail, no files, no directory access.
Network restriction
Limit an office to its own address ranges. Applied to every request, including each individual calculation — not only at sign-in. It runs alongside single sign-on rather than instead of it.
Accessibility
Built in from the start, not retrofitted
Virginia localities have accessibility procurement requirements, and a dense line-item tax form is exactly the interface that fails them when accessibility is added at the end.
- Every field has a real label naming its line number and description
- Line numbers are row headers, so a screen reader announces the context
- Fully operable by keyboard, with Enter and Shift+Enter moving between fields
- Visible focus indicators throughout, not the browser default
- Recalculated totals announced to assistive technology as they change
- Worksheets open as real dialogs, with focus handling and Escape to close
Licensing
Bought the way your office actually buys
Annual license, per office
One license covers your office for a tax year. Choose a floating number of simultaneous users, or single sign-on for named staff.
Purchase order and invoice
No card on file, no subscription to cancel, no automatic renewal charge. We invoice; you pay the way you pay for everything else. Renewal reminders arrive at 60 and 30 days.
A grace period, not a cliff
If a renewal is still working its way through procurement, access continues through a grace period with a visible reminder rather than stopping on the renewal date.
Your own address and branding
Your office gets its own address — yourcounty.tabren.com
— or your own domain, carrying your logo and colors. Staff see your
office's name, not ours.
See it against a return you already know
The most useful demo is one where you bring a completed Form 760 and check ours against it, line by line. Fifteen minutes, no obligation.