Contemporaneous records. Audit-ready exports. For every client.
Your clients arrive at tax time with a spreadsheet they built from memory in April. Auditors don't accept reconstructions. Tax Days gives each client a contemporaneous, day-by-day log they keep all year, then exports the audit-ready PDF and CSV you can drop straight into a residency file.
What you're up against
Clients reconstruct their year in April
A spreadsheet assembled from memory months later isn't contemporaneous. It's the first thing an auditor discounts, and the hardest thing to defend when the day count is close.
Auditors reject reconstructed records
Day-count cases turn on the quality of the record. Auditors weigh contemporaneous logs against their own reconstruction from cell-tower, EZ-Pass, credit-card, and travel data, and reconstructed client spreadsheets usually lose.
New York and California audit aggressively
NY runs the most active residency-audit program in the country, and CA scrutinizes departing residents closely. When a client is near a threshold, the burden of proof effectively sits with them.
No defensible record across a book of clients
Tracking day counts for dozens of clients in spreadsheets is error-prone and impossible to standardize. You need one consistent, defensible record format you can rely on at filing and at audit.
What Tax Days does for you
Gives each client a contemporaneous, day-by-day presence log they maintain throughout the year, not a tax-time reconstruction.
Exports an audit-ready PDF per jurisdiction with day count, trip detail, and rule evaluations you can drop into a residency file.
Exports CSV for clients whose day data you want to reconcile against your own workpapers or import elsewhere.
Tracks every state and country a client sets foot in, counting partial days the way most statutory-residence rules do.
Projects when a client will cross a threshold, NY's 184 days, CA's presumption, the Substantial Presence Test, so you can advise before it's too late.
Lets each client run their own log on their iPhone, so you're reviewing a clean record instead of rebuilding one.
Stores data on the client's device with optional iCloud sync, no shared servers, no accounts you have to administer.
The rules you actually need to track
New York 184-day statutory residence
184 days plus a permanent place of abode makes a client a statutory resident, taxable on worldwide income. The single most-audited day-count rule.
Read the guide →California 9-month presumption
Nine months in California in a tax year creates a presumption of residence, layered on a facts-and-circumstances test that's harder to rebut than a clean threshold.
Read the guide →Statutory residence vs. domicile
Two independent ways a state taxes a client as a resident. A client can keep their domicile elsewhere and still be a statutory resident on day count alone.
Read the guide →Convenience-of-the-employer rule
NY and a handful of states tax remote workdays as in-state when the work is for the employer's convenience, a frequent surprise for clients who relocated.
Read the guide →Substantial Presence Test
The federal day-count test that determines resident-alien status for non-citizen clients, using the 31-day and weighted 183-day calculation.
Read the guide →Defending a residency audit
What a residency audit demands, the evidence requests, the timeline, and why a contemporaneous log is the foundation of the defense file.
Read the guide →
Free guides and tools
- Guide
What records auditors actually accept
Contemporaneous vs. reconstructed records, the distinction that decides close day-count cases.
- Guide
Defending a residency audit
A practitioner's walkthrough of the residency-audit process and the evidence you'll be asked to produce.
- Calculator
Free 183-day rule calculator
Set a client's state threshold (184 for NY) and see the projected crossover date in seconds.
- Calculator
Substantial Presence Test calculator
Run the weighted 3-year SPT calculation for non-citizen clients without rebuilding the formula by hand.
Common questions
What day-count evidence holds up in a residency audit?
Contemporaneous records: a log kept as the year happened, ideally corroborated by travel bookings, card activity, and location data. Auditors discount reconstructions built after the fact, and the burden of proof is usually on the taxpayer.
How can clients give me their day counts without spreadsheets?
Tax Days exports an audit-ready PDF and CSV per jurisdiction: the trip log, day totals, and each rule evaluation. Clients log trips in the app; you get a clean, consistent record instead of a hand-built spreadsheet each spring.
Does Tax Days give tax advice?
No. It's a record-keeping and calculation tool: it counts days against the rules the client selects and shows threshold progress. Interpretation, planning, and filing positions stay with you, which is exactly where clients need their CPA.
Which clients most need day tracking?
Anyone splitting the year across jurisdictions: snowbirds with two homes, remote workers between states, cross-border commuters, expats in their arrival or departure year, and nonresident aliens near the Substantial Presence threshold.
Give every client a record that holds up
Recommend Tax Days to your clients and review a clean, exportable log instead of rebuilding one at filing. It's $29.99/year per client, far less than the cost of one indefensible day-count case.
