Transferability Under §6418: A $100 Million Credit, Two Buyers, and No Second Sale
Harbor Solar Partnership places a utility-scale solar project in service with $250 million of qualified investment.
Assume the project satisfies prevailing wage and apprenticeship and earns a domestic-content bonus. For this worked example:
Qualified investment $250.0m
Base / PWA §48E rate 30.0%
Domestic-content bonus 10.0%
-------
Illustrative total §48E rate 40.0%
Total credit $100.0m
Harbor cannot use the full $100 million credit efficiently itself, so it decides to transfer the credit under §6418.
It does not need one buyer.
It sells 60% to Buyer A and 40% to Buyer B.
Buyer A specified credit portion $60.0m
Illustrative price 94.0¢
Cash paid $56.4m
Buyer B specified credit portion $40.0m
Illustrative price 93.0¢
Cash paid $37.2m
-------
Total credit transferred $100.0m
Total cash received $93.6m
Weighted cash price 93.6¢
Those prices are teaching assumptions, not a statement about the current market.
The legal mechanics are more interesting than the price.
Buyer A cannot later resell its $60 million credit. Harbor cannot sell the domestic-content bonus separately from the rest of the credit. A registration number does not prove the $100 million is allowable. If the credit is later reduced to $90 million, both buyers can face an excessive-credit-transfer adjustment. And if a standard §50 recapture event occurs, the buyer allocation depends on how much of the credit Harbor actually transferred.
Transferability is simple only if the model stops at cash proceeds.
Harbor is selling a tax credit, not the project
Section 6418 allows an eligible taxpayer to transfer all or a specified portion of an eligible credit to an unrelated transferee taxpayer for cash.
The buyer does not become an owner of Harbor Solar.
It does not receive:
- project equity;
- depreciation;
- operating cash;
- voting rights; or
- lender security.
It receives the transferred specified credit portion.
That distinction explains both the appeal and the limit of the structure.
Harbor turns a credit into cash without admitting a tax-equity investor into project ownership. But the depreciation remains with the owner, subject to the owner's ability to use it.
For a sponsor comparing transferability with a partnership flip, the right comparison is not:
$100m credit
versus
$93.6m transfer cash
It is:
Value of credit monetized through transfer
+
value of depreciation retained / usable by sponsor
versus
capital raised and tax value monetized through tax equity
+
incremental partnership cost and complexity
That is why transferability did not make tax equity disappear.
A $100 million credit can be split between buyers
The final regulations expressly allow multiple transfer elections for one eligible credit property, as long as the specified credit portions do not exceed the total credit.
Harbor therefore can sell:
60% → Buyer A
40% → Buyer B
without violating the transfer rules.
The important unit is the specified credit portion.
Each portion is a proportionate slice of the single overall eligible credit determined with respect to the property.
Harbor cannot carve the $100 million into:
$75m "base / PWA credit" → Buyer A
$25m domestic-content bonus → Buyer B
as though the bonus were a separate transferable asset.
The final regulations reject that horizontal split.
Instead, each transferred percentage carries its proportionate share of the components used to calculate the total credit.
For Harbor:
Total credit $100.0m
Base / PWA component $75.0m
Domestic-content component $25.0m
Buyer A receives 60%:
Base / PWA component $45.0m
Domestic-content component $15.0m
-------
Buyer A specified portion $60.0m
Buyer B receives 40%:
Base / PWA component $30.0m
Domestic-content component $10.0m
-------
Buyer B specified portion $40.0m
If the domestic-content position is wrong, it affects both buyers proportionately because it was part of the credit each one purchased.
That is a better way to model diligence than assigning one tax issue to one buyer.
The cash treatment is unusually clean
Harbor receives $93.6 million of cash.
Section 6418 requires the consideration for the transfer to be cash.
For federal income-tax purposes:
- Harbor does not include the cash consideration in gross income; and
- Buyers A and B do not deduct the purchase price.
The discount itself is not taxable income to the buyer merely because the buyer paid less cash than the face amount of the credit.
Buyer A paid $56.4 million for a $60 million specified credit portion.
The $3.6 million difference is not, by itself, gross income to Buyer A under the final regulations.
Economically, it is the buyer's return if the credit can actually be used.
That last condition matters.
Harbor is a partnership, so the sale also changes partner basis
Assume Harbor Solar Partnership has two partners and, before the transfer, their distributive shares of the otherwise eligible credit are:
Partner Alpha 70%
Sponsor 30%
Harbor transfers the entire $100 million credit and receives $93.6 million of cash.
For partnership tax purposes, the transfer consideration is tax-exempt income.
If the whole credit is transferred, the simple version of the allocation follows the partners' otherwise eligible credit shares:
Partner Alpha tax-exempt income
= $93.6m × 70%
= $65.52m
Sponsor tax-exempt income
= $93.6m × 30%
= $28.08m
That tax-exempt income generally increases outside basis under §705.
It does not mean $65.52 million of cash must physically be distributed to Partner Alpha and $28.08 million to the sponsor.
Tax allocation and cash distribution are separate schedules.
The final §6418 regulations also treat this tax-exempt income as arising from an investment activity rather than from the conduct of a trade or business. For partners subject to §469, it therefore does not automatically become passive income that frees passive losses.
This is the same ledger problem that appears in Outside Basis and Suspended Losses: a transaction can increase outside basis and still fail to solve a different limitation.
Harbor still takes the investment-credit basis reduction
Selling the credit does not let Harbor keep full depreciable basis.
Section 6418 tells the owner to apply §50(c) as though the transferred investment credit had been allowed to the eligible taxpayer.
For Harbor's $100 million §48E credit, §50(c) takes only 50% of the clean electricity investment credit into account for the basis reduction.
Qualified investment $250.0m
50% of $100m credit (50.0m)
-------
Post-credit tax basis before depreciation $200.0m
Harbor receives $93.6 million of tax-exempt transfer cash and still depreciates a $200 million basis rather than $250 million.
The buyer gets the credit.
The property owner keeps the basis consequence.
That separation becomes even more important if the credit is later recaptured, because basis restoration remains with the property owner while standard transferred-credit recapture can sit with the buyer.
Registration is a gate, not an IRS opinion
Before Harbor can make the transfer election, it has to complete pre-filing registration and obtain the required registration number for the eligible credit property.
Each eligible credit property needs its own registration number.
The number is valid for one taxable year and must be renewed when required for a later year.
Harbor and the transferee also need to report the registration number in the required return package.
But the final regulations are explicit on the important point:
receiving a registration number does not mean the IRS has concluded Harbor is entitled to transfer the credit.
For Harbor, registration does not prove that:
- $250 million is the correct qualified-investment amount;
- the project satisfied PWA;
- the domestic-content bonus is valid;
- the project passed current PFE restrictions; or
- the $100 million credit is otherwise allowable.
Registration is procedural.
Credit eligibility remains substantive.
A buyer that treats the registration number as tax diligence has confused permission to file with approval of the position.
The election deadline is strict, but the six-month relief is narrower than it sounds
Harbor's transfer election is generally made on the original return for the taxable year in which the credit is determined, by the due date including extensions.
The election is irrevocable.
A buyer cannot rely on a commercial agreement alone. The tax election still has to be made correctly.
The final regulations also acknowledge automatic relief under §301.9100-2(b), but this is not a general right to repair any missed transfer later on an amended return.
The relief requires, among other things, that the taxpayer:
- timely filed the return for the year the election should have been made;
- did not receive an extension of time to file beyond the original due date;
- takes corrective action within the six-month extension period; and
- follows the procedural requirements in §301.9100-2(d).
So the model should not contain:
Election missed
→ fix later
It should contain:
Election / filing deadline
→ closing condition and tax-return workstream
Potential 9100-2(b) relief
→ narrow exception requiring tax review
That is a materially different risk posture.
Buyer A cannot resell the credit if its tax appetite changes
A specified credit portion may be transferred only once.
Buyer A acquires $60 million.
Assume Buyer A expected to use all $60 million but its actual current-year §38 limitation allows only $45 million.
Purchased credit $60.0m
Current-year usable amount $45.0m
-------
Unused amount $15.0m
Buyer A cannot solve that mismatch by selling $15 million to Buyer C.
The no-additional-transfer rule blocks a second §6418 transfer of the purchased credit.
For applicable credits such as §48E, the final regulations allow a transferee to use the §39 carryback and carryforward regime, including the special three-year carryback rule for applicable credits, subject to the normal limitations.
That is useful.
It is not the same as liquidity.
Buyer A paid cash now for a credit it may use in a different tax year.
For credit underwriting, "tax appetite" therefore means more than annual federal tax liability. It means the amount the buyer can actually claim after §38, §469 where applicable, and the buyer's own carryback / carryforward position.
Individuals can buy, but §469 can make the credit much less useful
Transferability is not legally limited to C corporations.
But the passive-activity rules can sharply constrain individuals and other taxpayers subject to §469.
The final regulations treat a transferred specified credit portion as arising in connection with the trade or business that generated the credit.
If an individual transferee did not materially participate in that activity, the transferred credit is generally treated as arising from a passive activity for that individual.
That means a buyer can legally purchase a credit and still be unable to use it against the tax liability it expected.
Buyer diligence therefore includes the buyer's own limitation analysis.
The seller cannot solve that with a stronger tax opinion on the project.
One project, two buyers, one recapture event
Now move Harbor into the standard §50 recapture period.
Assume a project-level event occurs when the standard recapture percentage is 60%.
The original credit was $100 million.
Standard project-level recapture
= $100m × 60%
= $60.0m
Harbor transferred 60% to Buyer A and 40% to Buyer B.
The standard project-level transferred-credit recapture follows that split:
Buyer A statutory recapture share
= $60.0m × 60%
= $36.0m
Buyer B statutory recapture share
= $60.0m × 40%
= $24.0m
The purchase agreements can require Harbor, the sponsor or another guarantor to indemnify the buyers.
That is a commercial risk transfer.
The statutory tax initially sits with the transferees for the transferred portions.
There is one important exception to the slogan "the buyer bears recapture."
If Harbor were a tax-equity partnership and a partner's reduction or disposition of its partnership interest created indirect partner-level recapture, the final §6418 regulations do not shift that partner-level recapture to the third-party credit buyer.
Project-level standard recapture and partner-level indirect recapture are different events.
ITC Recapture After 2025 runs that distinction numerically.
Now reduce Harbor's $100 million credit to $90 million
Assume Harbor sells the full $100 million credit, but the IRS later concludes that the allowable credit was only $90 million.
The total excessive credit transfer is $10 million.
Because Buyer A bought 60% and Buyer B bought 40%, illustrate the adjustment proportionately:
Buyer A:
Claimed portion $60.0m
Allowable 60% share of $90m $54.0m
-------
Excess $6.0m
20% additional amount $1.2m
-------
Buyer A tax increase $7.2m
Buyer B:
Claimed portion $40.0m
Allowable 40% share of $90m $36.0m
-------
Excess $4.0m
20% additional amount $0.8m
-------
Buyer B tax increase $4.8m
Across both buyers:
Underlying credit overstatement $10.0m
20% additional amount $2.0m
-------
Combined buyer exposure $12.0m
The 20% additional amount does not apply if the transferee establishes reasonable cause.
The final regulations deliberately do not create a bright-line diligence safe harbor.
The buyer's efforts to determine that the seller actually had the credit to transfer are a central reasonable-cause factor, and reliance only on the seller's representations is not enough.
That is why Harbor's buyer diligence reaches into:
- eligible basis;
- PWA;
- domestic content;
- energy community, if applicable;
- PFE / material assistance;
- placed-in-service;
- ownership;
- registration; and
- the underlying credit calculation.
The buyer is purchasing a tax position, not a PDF certificate.
The 2025 law added a buyer-status screen
Harbor's project is using §48E.
Current §6418 now prohibits transfers of specified credits, including §48E credits, to a specified foreign entity.
So Harbor's buyer checklist has two independent status tests:
Related to Harbor under §267(b) / §707(b)(1)? NO
Specified foreign entity? NO
The first rule has been part of §6418 from the beginning.
The SFE prohibition was added in 2025.
For a current transfer agreement, an unrelated-party representation is therefore no longer enough for the affected credits.
Buyer-status diligence has to cover both.
A forward sale can matter before the credit exists
Harbor expects $93.6 million of transfer proceeds.
The credit will not be transferred until the tax requirements are satisfied, but the commercial purchase agreement can be signed earlier and used as part of a financing package.
Suppose Harbor has a committed forward purchase arrangement covering the full modeled $93.6 million of cash consideration and its bridge lender applies an illustrative 80% advance rate to eligible contracted proceeds.
Modeled contracted transfer proceeds $93.6m
Illustrative bridge advance rate 80.0%
-------
Illustrative bridge availability $74.88m
The 80% rate is a financing assumption, not a market rule.
The point is structural.
A forward buyer commitment can turn a future tax-credit sale into a receivable that a lender can analyze for bridge purposes.
The bridge still has to haircut:
- conditions precedent to the buyer's payment;
- seller indemnity exposure;
- registration and election risk;
- credit eligibility;
- buyer credit quality; and
- timing of receipt.
So the right question is not merely "spot price or forward price?"
It is:
What financing value does the committed purchase agreement create after the lender's eligibility and advance-rate assumptions?
That is often the more important model line.
Transferability is not direct pay for a different taxpayer
Harbor is an eligible taxpayer under §6418.
An applicable entity under §6417 is generally excluded from being an eligible taxpayer for §6418.
So a municipal utility cannot normally look at Harbor's transaction and choose between:
Sell §48E credit under §6418
or
take direct pay under §6417
as two equivalent routes for the same owner.
Entity status changes the available regime.
That is why Direct Pay Under §6417 should be read as a different eligibility architecture, not merely as a 100-cent transfer.
For an ordinary taxable sponsor like Harbor, the closer comparison is transferability versus using tax equity or retaining the credit.
Harbor's transfer model
The model should separate credit validity, sale economics, buyer use and post-closing risk.
1. Credit determination
Qualified investment $250.0m
Base / PWA rate 30.0%
Domestic-content bonus 10.0%
-------
Total credit $100.0m
2. Buyer split
Buyer A portion 60.0%
Buyer B portion 40.0%
Total transferred 100.0%
Check 100.0%
The model should reject an aggregate transfer above 100%.
3. Cash proceeds
Buyer A: $60m × 94.0% $56.4m
Buyer B: $40m × 93.0% $37.2m
-------
Total cash $93.6m
Effective cash price 93.6¢
Then subtract actual seller-paid legal, diligence, insurance, escrow and buyer-cost reimbursements from the term sheets.
Do not hard-code a generic market friction assumption.
4. Buyer tax-capacity schedule
Buyer A purchased credit $60.0m
Current-year usable $45.0m
Unused $15.0m
Resale allowed? NO
Carry rules §39 analysis
This is where the buyer's tax department belongs in the transaction model.
5. Partnership tax allocation
Transfer cash $93.6m
Partner Alpha tax-exempt share 70.0%
Sponsor tax-exempt share 30.0%
Alpha tax-exempt income $65.52m
Sponsor tax-exempt income $28.08m
Keep the cash-distribution waterfall separately.
6. Owner basis
Starting tax basis $250.0m
§50(c) reduction: 50% × $100m (50.0m)
-------
Post-credit basis $200.0m
7. Downside
Credit later allowed $90.0m
Excessive transfer $10.0m
20% additional amount $2.0m
Combined exposure before reasonable cause $12.0m
And separately:
Standard project-level recapture % 60%
Recapture amount $60.0m
Buyer A statutory share $36.0m
Buyer B statutory share $24.0m
Those are different risks and should not sit in one "tax indemnity" row.
The transaction checklist follows the same sequence
For Harbor, the useful closing and diligence questions are concrete.
- Is Harbor an eligible taxpayer for §6418 rather than an applicable entity under §6417?
- What is the eligible credit property and the amount of the credit determined with respect to it?
- Does each specified credit portion include the correct proportionate share of bonus amounts?
- Do all transfer elections aggregate to no more than 100% of the credit?
- Is every buyer unrelated under the §267 / §707 rules?
- For the affected current credits, is every buyer confirmed not to be an SFE?
- Has Harbor completed pre-filing registration for the correct property and taxable year?
- Does anyone understand that the registration number is procedural rather than substantive approval?
- Is the election workstream scheduled for the original-return deadline?
- If anyone is discussing late-election relief, do the narrow §301.9100-2(b) conditions actually fit?
- What amount can each buyer use after its own §38 and §469 limitations?
- What carryback / carryforward value does unused credit have to that buyer?
- What diligence supports the buyers' reasonable-cause position if the credit is later reduced?
- How are standard project-level recapture and partner-level indirect recapture allocated?
- If Harbor is a partnership, how is §6418 tax-exempt income allocated and what does it do to outside basis?
- Where do transfer proceeds go in the financing waterfall and, if bridged, what lender haircut applies?
Harbor started with a $100 million credit.
By the end of the transaction, there are at least four different numbers:
$100.0m tax credit determined
$93.6m illustrative transfer cash
$60.0m Buyer A credit position
$40.0m Buyer B credit position
And none of them answers the next question by itself.
The credit still has to be valid.
The buyers still have to be able to use it.
The seller still has a reduced tax basis.
The partnership still has basis and allocation consequences.
The election still has to be made correctly.
And a credit that has already moved once is no longer a tradable asset.
That is §6418 in a financing model.
Primary sources: 26 U.S.C. §6418 — Transfer of Certain Credits · Treasury/IRS — §6418 Final Regulations, T.D. 9993 · 26 U.S.C. §39 — Carryback and Carryforward of Unused Credits · 26 U.S.C. §50 — Recapture and Basis Adjustments · IRS — 2025 Instructions for Form 3800