Crypto Tax Form 8949 Guide (2026): How to Reconcile 1099-DA When Your Exchange Omits Cost Basis

Your exchange sent a Form 1099-DA. It shows what you sold your crypto for, but the cost basis box is blank. What do you put on Form 8949? For a 1099-DA with no basis, check box H (held one year or less) or box K (held more than a year), enter the proceeds from the form, and fill in your own cost basis. Do not use box B, E, C or F. Those are the old boxes, and some guides still teach them. This guide walks through each step with a worked example for card rewards and a simple swap, and no paid tax software is needed.

This page is general information, not tax advice. Tax treatment depends on your facts, so consult a qualified tax professional before filing. CryptoCashbackCard is an independent site, not affiliated with any exchange or card issuer. This page has no affiliate or referral links.

The short answer

• Box H or K. A 1099-DA with no basis (or basis not reported to the IRS) goes on Form 8949 with box H checked (short-term, Part I) or box K checked (long-term, Part II).
• Column (d) is the form’s proceeds. Copy the proceeds from the 1099-DA exactly.
• Column (e) is your job. Blank basis does not mean $0. Enter what you actually paid, including fees. If you leave it empty, the form implies the whole amount was profit.
• No form at all? Use box I (short-term) or box L (long-term). You still have to report the sale.
• Do not use B, E, C or F for crypto. The IRS says digital asset transactions should not be reported using box C or F, and B and E are worded for Form 1099-B.

The 2025 Form 8949 boxes for crypto

The 2025 form added six new boxes for digital assets. Check only one box per page, and use a separate Part I or Part II page for each box you need.

You have…	Held 1 year or less (Part I)	Held more than 1 year (Part II)
A 1099-DA that shows basis was reported to the IRS (box 2 checked)	Box G	Box J
A 1099-DA with no basis, or basis not reported to the IRS	Box H	Box K
No 1099-DA or 1099-B for the sale	Box I	Box L
Old boxes: B/E (for Form 1099-B), C/F (non-crypto, no form)	Not for crypto

Sources: IRS Instructions for Form 8949 (2025), 2025 Form 8949.

Why some guides say box B or E

Before 2025, crypto had no box of its own. Many people used C and F because they had no 1099. Some guides have simply moved those readers one box over to B and E. At least one crypto tax guide written for 2025 returns tells readers the new 1099-DA moves crypto into box B or E and lists only the old six boxes. The IRS instructions say otherwise: “Digital asset transactions should not be reported using box C or F. Instead, digital asset transactions should be reported using box G, H, or I for short-term transactions. Box J, K, or L should be used to report long-term transactions.” If your preparer or software uses B or E for a 1099-DA, ask why.

Step by step: reconcile a 1099-DA with no cost basis

Step 1. Gather your papers

• Every 1099-DA you received. Each exchange sends its own.
• Your purchase receipts, including the fees you paid.
• Your card rewards payout history (date, coin, amount, dollar value when credited).
• Records of any transfers into the exchange from a wallet or another exchange.

The IRS says to keep records of every purchase, receipt, sale, exchange or other disposition, and the dollar value of anything you received as income.

Step 2. Read the 1099-DA boxes that matter

Box	What it shows	What you do with it
1b, 1c	Name of the asset and number of units sold	Column (a) of Form 8949
1d	Date acquired. Can be blank for noncovered assets or when bought on various dates	Column (b) if filled. Otherwise use your records
1e	Date sold	Column (c)
1f	Proceeds (includes the value of crypto you received in a swap)	Column (d), exactly as shown
1g	Cost or other basis. Often blank for 2025	Blank = find it yourself. See the warning below about $0
2	Checked = basis was reported to the IRS	Checked: box G or J. Not checked: box H or K
9	Checked = noncovered asset, so boxes 1d, 1g, 2 and 6 may be blank	Expect to supply your own basis
6	Short-term or long-term (may be blank)	Check it against your own dates
12a, 12b	Units transferred in, and the date	A clue that the crypto was not bought at this exchange
“Applicable checkbox on Form 8949” (top of form)	A one-letter code. G, H, J, K, or Y	A hint only. See “A note on code Y” below

Source: 2025 Form 1099-DA, recipient copy and instructions.

A note on code Y

For 2025, the IRS told brokers to put code Y in the “Applicable checkbox” box when they do not report basis. The IRS defines Y as “cannot determine whether the recipient should check box H or box K … because the holding period is unknown.” So code Y does not tell you short-term or long-term. You decide that from your own dates (Step 4).

Step 3. Sort each sale: short-term or long-term

One year or less is short-term (Part I). More than one year is long-term (Part II). The count starts the day after you got the asset and includes the day you sold it. If you sold a batch you bought on different dates, you can use “VARIOUS” as the acquired date, but the short-term and long-term pieces still go on separate parts.

If you bought, swapped or earned some of the same coin at different times, you also need to know which units you sold. The IRS has rules for this, which are separate from the 8949 boxes. If you do not identify the units yourself, the default for a wallet is earliest-acquired first. For units held at a broker in 2025, IRS Notice 2025-7 temporary relief lets you identify them in your own records before the sale. Ask a tax professional if you have a lot of lots (IRS digital asset FAQs, Q82 to Q88).

Step 4. Find your basis for each sale

How you got the crypto	Your basis is usually
Bought with dollars	The dollars you paid plus the purchase fee
Received in a swap (for example, bitcoin for ether)	The dollar value of what you received at the time of the swap. Swap fees are not added to it (they were counted against the crypto you gave up)
Card rewards	Unsettled. The IRS has not said. See the card rewards section below
Moved in from your own wallet or another exchange	The basis from where you originally got it. The transfer itself is not a sale

Sources: IRS digital asset FAQs (Q56 purchases, Q72 swaps, Q81 transfers), Form 8949 instructions (“the basis of a digital asset is the cost to acquire the digital asset, including transaction fees, commissions, transfer taxes, and other acquisition costs”).

Step 5. Fill in the columns

Column	What to enter for a 1099-DA with no basis
(a) Description	The asset and the exact units, for example “0.02 BTC”. Add the transaction ID if you have it
(b) Date acquired	Your real purchase or receipt date, or VARIOUS
(c) Date sold	Box 1e of the 1099-DA
(d) Proceeds	Box 1f of the 1099-DA, exactly
(e) Cost or other basis	Your own basis from Step 4
(f) Code, (g) Adjustment	Usually blank. Only use them to fix something. See “fees” below
(h) Gain or (loss)	(d) minus (e), adjusted by (g). Losses go in parentheses

The IRS says that for most transactions you can leave columns (f) and (g) blank, and that you may round to whole dollars if you round every amount. One row per transaction is the rule. If you have a lot, the IRS lets you attach a statement with the same columns instead (the instructions call it Exception 2).

The skip-8949 shortcut does not apply to you. The IRS lets you total some 1099-DA sales straight onto Schedule D (lines 1a and 8a) without Form 8949, but only when the form shows basis was reported to the IRS and nothing needs fixing. A blank-basis 1099-DA does not qualify.

Fees

Fees count. In the IRS’s terms, “digital asset transaction costs” such as network (gas) fees, commissions and transfer taxes reduce your proceeds when you sell and add to your basis when you buy. Check whether the 1099-DA already includes them. Coinbase’s help says its US trading fees are already included in basis and subtracted from proceeds. If a fee is not reflected on the form, the IRS says to enter it as a negative number in column (g) with code E in column (f). Do not subtract the same fee twice.

Step 6. Add up and send totals to Schedule D

Each Form 8949 page has a totals row. The IRS tells you where each box’s total goes on Schedule D:

Box checked	Schedule D line
G (short-term, basis reported)	1b
H (short-term, basis not reported)	2
I (short-term, no 1099)	3
J (long-term, basis reported)	8b
K (long-term, basis not reported)	9
L (long-term, no 1099)	10

Source: totals rows on the 2025 Form 8949. Then answer the digital assets question on Form 1040. If you received a 1099-DA, the IRS says to check “Yes.”

Step 7. Tie it out

Add up the column (d) proceeds on all your rows for one exchange. It should match the total of the proceeds (box 1f) on that exchange’s 1099-DA. If it does not, you may have missed a sale or typed a number wrong. The IRS says Form 8949 exists so that you and the IRS can “reconcile” what was reported on the 1099-DA with what you report, so do this check before you file.

Card reward disposals and simple swaps: a worked example

Illustration only. All numbers below are made up and are not from a real account. They are not real bitcoin prices.

What the 1099-DA shows (made-up)

Line	1b / 1c	1e Date sold	1f Proceeds	1g Basis	Box 9
1	BTC, 0.02	09/12/2025	$2,000	blank	Noncovered
2	BTC, 0.01 (swapped for ETH)	06/01/2025	$700	blank	Noncovered
Total proceeds on the form			$2,700

What your own records show (made-up)

• Line 1: the 0.02 BTC came from 12 card reward payouts credited between February and August 2025. The dollar value on the days they were credited adds up to $1,500. Assumption: we use that value as basis. The IRS has not said what basis card rewards have, so this is one common approach, not a rule. Everything was held a year or less.
• Line 2: 0.01 BTC bought on 02/01/2024 on another platform for $380 plus a $20 fee, so basis $400. It was moved to the exchange in 2025, which is why Box 9 shows noncovered. It was held more than a year before the 06/01/2025 swap.

The filled-in Form 8949 rows

Part I, box H checked (short-term, 1099-DA, basis not reported):

(a)	(b)	(c)	(d)	(e)	(f), (g)	(h)
0.02 BTC	VARIOUS	09/12/2025	2,000	1,500	blank	500
Totals (to Schedule D, line 2)			2,000	1,500		500

Part II, box K checked (long-term, 1099-DA, basis not reported):

(a)	(b)	(c)	(d)	(e)	(f), (g)	(h)
0.01 BTC	02/01/2024	06/01/2025	700	400	blank	300
Totals (to Schedule D, line 9)			700	400		300

Tie-out: $2,000 + $700 = $2,700 in column (d), the same as the $2,700 of proceeds on the 1099-DA. Total gain: $500 short-term plus $300 long-term.

What happens to the ETH from the swap: your basis in the new ETH is its dollar value when you received it ($700 in this example). Your holding period for it starts the day after the swap. If you later sell or spend that ETH, it is a new row with that basis (IRS FAQ Q72 and Q74).

Not on the form: moving crypto between wallets you own is not a sale (IRS FAQ Q81), so it gets no row. The exception is crypto used to pay the network fee. That is a small disposition. Coinbase says only that crypto sold or used to pay the fee is reported on the 1099-DA.

Spending reward crypto

If you spend reward crypto on a purchase, you have disposed of it. The IRS says that exchanging digital assets for other property, or paying for services with them, produces a capital gain or loss (IRS FAQ Q62, Q64, Q65). The row looks like the ones above: the dollar value you got as proceeds, your basis, and the gain or loss. If a payment processor or exchange sent you a 1099-DA, use box H or K. If nobody sent you a form, use box I or L.

For the bigger question of whether card rewards are income when you earn them, see Are crypto credit card rewards taxable? For what Coinbase itself sends and where to download it, see Coinbase taxes: forms, reports and how to file.

What your exchange will and won’t give you

Exchange	1099-DA for 2025	Form 8949
Coinbase	Proceeds only. Basis starts with 2026 sales, for “covered” assets only	Not provided from tax year 2025. Points to a CoinTracker plan. Notes the IRS has an editable PDF
Gemini	Proceeds only. Add basis and date for transferred-in assets in your account’s tax settings	“Does not prepare or issue Form 8949”
Kraken	Gross proceeds to the IRS. Your copy shows a FIFO estimate that is not reported to the IRS	Not confirmed in the Kraken page we read. Kraken says missing basis does not mean $0 and to use your own records

Sources: Coinbase Help: Form 1099-DA, Coinbase Help: Form 8949, Coinbase Help: edit transaction details, Gemini Support: crypto tax reporting, Kraken Support: your 2025 Form 1099 (all checked Oct. 26, 2026; exchange pages change often).

Coinbase’s help also says that for crypto received from outside the exchange, it estimates a basis of $0 in its own tax tool, “because the IRS may assume a $0 cost basis if you don’t report cost basis.” Do not copy an estimated $0 onto your return without checking it against your records.

Common mistakes

• Using box B, E, C or F for crypto. Use G, H, I, J, K or L.
• Leaving column (e) blank, or typing $0. That makes the whole proceeds look like profit. Enter your real basis.
• Treating a printed $0 in box 1g as “no basis reported.” A zero entry counts as reported basis. Check box 2.
• Reading code Y as short-term or long-term. It is neither. Use your own dates.
• Adding a fee twice. Check whether the form already reduced proceeds or added to basis before using code E.
• Using the transfer date as the purchase date. For crypto you moved in, the exchange’s receipt date is a placeholder. Use your original purchase date, or short and long-term can come out wrong.
• Skipping a swap. A crypto-to-crypto trade is a sale. It shows up on the 1099-DA and needs a row.
• Skipping sales with no form. The IRS says you report digital asset transactions whether or not you get a form.
• Using the Schedule D shortcut on a blank-basis form. It only works when basis was reported and no fixes are needed.

What we could not confirm

FAQ

Which Form 8949 box do I use for a 1099-DA with no cost basis?

Box H if you held the crypto one year or less (Part I). Box K if you held it more than a year (Part II). Enter the form’s proceeds in column (d) and your own basis in column (e).

Is box B or box E ever right for crypto?

The 2025 form words B and E for Form 1099-B. The IRS instructions say to use G, H or I (short-term) and J, K or L (long-term) for digital assets.

What if my 1099-DA shows $0 in the cost basis box?

The IRS says any entry in box 1g, including zero, has been reported to the IRS as basis. Check whether box 2 is checked. If it is, use box G or J, enter the form’s basis in column (e), and correct it with an adjustment in column (g). If you are not sure, ask your exchange or a preparer.

What does code Y on my 1099-DA mean?

For 2025, brokers could use it when they did not report basis. The IRS defines it as holding period unknown, so choose box H or K from your own dates.

Does Coinbase give me a completed Form 8949?

Not from tax year 2025. Coinbase says its Retail Tax Center no longer provides it. The IRS publishes a fillable form, and tax software or a preparer can produce it.

I never got a 1099-DA. Do I still report the sale?

Yes. Use box I (short-term) or L (long-term) and enter the sale yourself. The IRS says to report digital asset transactions whether or not you receive a form.

Do I need Form 8949 if my basis was reported?

Not always. If every 1099-DA shows basis reported to the IRS, you need no corrections, and nothing else applies, you may be able to enter totals directly on Schedule D (lines 1a and 8a). That is the IRS’s “Exception 1.”

Is spending my card reward crypto a taxable event?

Yes. The IRS treats paying with digital assets as a disposition, and you figure gain or loss against your basis. What basis to use for card rewards has not been settled by the IRS.

Sources

• IRS: Instructions for Form 8949 (2025)
• IRS: 2025 Form 8949
• IRS: 2025 Form 1099-DA (recipient instructions)
• IRS: 2025 Instructions for Form 1099-DA
• IRS: Digital assets
• IRS: Frequently asked questions on digital asset transactions
• Coinbase Help: IRS Form 1099-DA
• Coinbase Help: Form 8949
• Coinbase Help: edit transaction details
• Coinbase Help: Taxes for US customers
• Gemini Support: What Gemini provides for U.S. crypto tax reporting
• Kraken Support: How to read your 2025 combined Form 1099

Disclaimer

This page is general educational information, not tax, legal or financial advice. Tax rules depend on your individual facts and can change. The example numbers are made up and are not from a real account. Exchange help pages are updated often; we checked them on Oct. 26, 2026. The IRS has not issued guidance specific to crypto credit card rewards, and the treatment described here may not apply to you. Consult a qualified tax professional before making decisions or filing a return. CryptoCashbackCard is an independent site, not affiliated with or endorsed by any exchange or card issuer. This page has no affiliate or referral links.

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