A permanent federal deduction — §170(p), signed July 4, 2025 — returns real money to 150 million standard-deduction households for the first time, starting with refunds that land in spring 2027. Behavioral science says 60–75% of it dissolves into everyday spending within 90 days. Giving Tax Day is the pre-commitment architecture that redirects it back to the causes that earned it — automatically, at national scale, every year.
Every charitable dollar carries a hidden government match — but since 2017, 90% of households (teachers, nurses, service workers) were locked out of it by the standard deduction. §170(p) reopens the door: up to $1,000 single / $2,000 joint, permanently, from tax year 2026.
Research is unambiguous: 60–75% of tax refunds are absorbed into discretionary spending within 90 days (Souleles 1999; Parker et al. 2013). Without architecture, the $6.9B dividend lands in May and dissolves into rent, groceries, and summer travel by June. Every year.
Giving Tax Day pairs the GivingTuesday moment of intent with a Ulysses Pact: the donor pre-authorizes the redirect before the refund ever becomes "personal money." At a conservative 12% redonation rate, that's ~$840M/year of net-new charitable capital.
In one sentence: GivingTuesday is when America decides to give. Giving Tax Day is when the tax code makes sure it arrives.
Consulting rule number one: never show a big number without showing how it shrinks. This is the honest waterfall, from the total dividend §170(p) creates down to the conservative central estimate a partner can plan around.
USD, filing year 2026 onward · conservative pilot prior (ρ = 12% central)
Source: IRS Pub. 1304; JCT scoring of §170(p) OBBBA; Souleles (1999); Parker et al. (2013); Giving Tax Day Monte Carlo model, 10,000 iterations (White Paper Rev 4.2, May 2026). Intermediate bars are illustrative decompositions; end points ($6.9B, $840M P50) reconcile exactly with White Paper Rev 4.2, §3–4.
10,000 iterations · four-anchor triangulation of ρ
Even the pessimistic tail (P10) exceeds the annual online volume of most single giving platforms. The distribution is published, reproducible, and open to challenge.
Falsification criteria are stated in advance: if §170(p) take-up falls to ≤15%, if no RCT arm shows a significant effect, or if CBO/JCT scores the redirect above $5B in behavioral cost, the model is invalidated — and we will say so publicly. Partners are invited to stress-test every number. See the evidence base ↓
Most donors — and many nonprofit boards — have never seen the government's co-investment in their generosity written down. This form makes it visible in four lines.
Enter a donation. The form computes the §170(p) refund a standard-deduction household actually receives the following May — and what happens when a December pre-commitment redirects it.
Giving platforms: this is the widget your donors should see at checkout. Nonprofits: this is the number your thank-you letter should contain. Both playbooks below ↓
This isn't a generosity problem — it's a design problem. The intervention moves the decision to the moment of maximum motivation and lets automation carry it across the five-month gap.
At peak motivation, the donor pre-authorizes the May redirect — before the refund exists as psychological "personal money." No willpower required in May, because no second decision exists in May.
The receipt shows the household's Social Dividend estimate. The donor is no longer just a giver — they are a co-investor with the U.S. Treasury, responsible for where the match lands.
By this date, 92% of refunds have settled. The redirect runs on rails — Regulation E compliant, 14-day pre-notification, one-click cancellation through May 1 — visible and shareable like a GivingTuesday gift.
The GivingTuesday complement, not competitor: GivingTuesday answers "will I give?" — the world's largest day of intent. Giving Tax Day answers "did it arrive?" — the missing second half of the giving calendar. One built the culture; the other makes the culture survive contact with a bank statement.
The whole model hinges on one parameter: ρ, the share of eligible refund dollars that get redirected. We triangulate it from four anchors (6–22% range, 12% central). Drag the slider and see what the market looks like under your own assumption.
Analysis without implications is trivia. Here is what a giving-software company and a nonprofit should each do this quarter to be ready when 150 million refunds land in spring 2027.
You already hold the two seconds that matter: the instant a donation is confirmed. §170(p) turns that instant into a product surface no competitor has shipped yet.
Add one computed line to every 2026 donation confirmation: "Your estimated §170(p) refund: $X, arriving ~May 2027." Low lift, immediate differentiation, and it seeds the identity effect.
One opt-in checkbox (never pre-checked — UDAAP) at checkout in Nov–Dec 2026: "Redirect my refund to this cause on Giving Tax Day." Regulation E rails, 14-day pre-notification, cancel through May 1.
Join the Give More Tomorrow RCT as a technology partner. Your A/B infrastructure plus our pre-registered design = the first published evidence in the category, with your logo on it.
Treat Giving Tax Day like GivingTuesday's spring twin: leaderboards, shareable "my refund became a gift" moments, partner co-marketing. First mover defines the category.
77–81% of first-time donors never give again. §170(p) gives you a legitimate, valuable reason to contact every one of them twice more — with money attached.
From January 2027, every acknowledgment for a 2026 gift should state the donor's estimated refund. You're not asking for money — you're delivering good news about money they're owed. Open rates follow.
On GivingTuesday, offer the pre-commitment alongside the gift: "Make your refund a second gift — decide once, done in May." One decision, two donations, zero extra cost to the donor's December budget.
Reframe donors as co-investors with the Treasury. Identity labeling lifts follow-through 15–25% in the literature — and it's free. Toolkit templates available from the initiative.
Giving Tax Day gives your calendar a second national peak, five months after year-end. Report the redirected dollars publicly — "the tax code funded 40 scholarships" is a story local press runs.
givemoretomorrow.org is the open-science arm of the initiative — a 4-arm RCT (N≈2,000) across Minnesota, Arizona and Texas, running in filing season 2027. All results are published, favorable or not. The design descends directly from Thaler & Benartzi's Save More Tomorrow, applied to refund flows instead of paychecks.
Converts a one-time donor into a committed giver, attacking the sector's costliest failure: 77–81% first-gift churn.
Reveals the Treasury's hidden co-investment to already-committed donors, with salary-linked escalation over time.
Reframes the question from "what can I afford?" to "what impact do I want?" — working backward from net cost after refund.
A recommendation you can't falsify isn't a recommendation. Every major risk carries a pre-published kill criterion.
| Risk | How it's held | Kill criterion |
|---|---|---|
| Low §170(p) take-up | Awareness is the product: the Social Dividend receipt puts the deduction in front of every donor at checkout, not buried in filing software. | Take-up ≤ 15% |
| Pre-commitment doesn't move behavior | Four-arm RCT, pre-registered, tri-state. The mechanism inherits a two-decade evidence base from Save More Tomorrow. | No significant effect in any arm |
| Regulatory / consumer-protection exposure | Conservative by design: Regulation E + NACHA rails, mandatory 14-day pre-notification, one-click cancellation through May 1, explicit opt-in only — never pre-checked. | UDAAP finding on the flow |
| Fiscal-cost backlash | The deduction already exists and is permanent; the redirect adds no new tax expenditure. Monitored against official scoring. | CBO/JCT scores redirect > $5B |
| Perceived commercial capture | Open science, open source, zero founder equity. All findings published — including unfavorable ones. | Any undisclosed financial stake |
Platform partners commit; Social Dividend receipt spec published; RCT partners locked for filing season.
Pre-commitment toggle live at checkout through GivingTuesday and year-end campaigns. The Ulysses Pact is signed at scale.
Civic Investor acknowledgments go out; RCT fields across MN/AZ/TX; refunds begin settling.
Redirects execute nationally. Results measured, published, and turned into the year-two playbook.
Giving Tax Day is the U.S. scale launch of a pattern born in Spain (Altruismo Fiscal, 2021) and validated through open research (Give More Tomorrow). The framework is portable — UK Gift Aid, Canada, Australia, corporate giving circles. Building a branch elsewhere? Tell us.
In Scenario A, 150 million refunds land unlabeled and dissolve by June — every year. In Scenario B, the December decision and the May refund become the same decision, executed automatically. The difference between the two scenarios is whoever builds the pipeline in the next two quarters. That could be you.
Prefer email? hello@givingtaxday.org · Or start with the White Paper.