New NFL fans who use our Underdog promo code TOPACTION unlock two brilliant shots at bonuses, one guaranteed to give you up to $1,000 in bonuses as a 50% deposit match. The DFS promo gives you entry into Keep Your Million. A first deposit of $10 activates both, and the match climbs to the full $1,000 for anyone funding an account with $2,000.
Thursday Night Football, Lions vs. Bills hands new users a perfect chance to make use of both as well, with Detroit travelling to Buffalo's new Highmark Stadium at 8:15 p.m. ET on Prime Video.
Both teams arrive 1-0 after chaotic Week 1 finishes; Josh Allen piled up 334 passing yards and four total touchdowns against Houston, and oddsmakers price the Bills as 3.5-point home favorites. Lions vs. Bills gives the Underdog promo code TOPACTION a big stage.
How Much Does the Underdog Bonus Code Match?
The Underdog promo code TOPACTION pays 50 cents on every dollar in bonus credits, so your deposit size sets your bonuses:
| Your deposit | Bonus funds (50%) | The math | Starting balance |
|---|---|---|---|
| $10 | $5 | $10 + $5 | $15 |
| $100 | $50 | $100 + $50 | $150 |
| $500 | $250 | $500 + $250 | $750 |
| $2,000 | $1,000 | $2,000 + $1,000 | $3,000 (maximum) |
Underdog credits the bonus on top of your own cash rather than replacing it, so both amounts sit in the account together. A $2,000 deposit maxes the offer, and anything above that earns no bonus.
Which Underdog Deposit Tier Fits You?
Bonus funds expire 14 days after they land, so your plans for the next two weeks matter more than the headline number. The 14-day window covers a loaded stretch, so map your entries before you pick a tier:
| Game | When | Where to watch |
|---|---|---|
| Saints at Ravens | Sunday, Sept. 20, 1 p.m. ET | CBS |
| Commanders at Cowboys | Sunday, Sept. 20, 4:25 p.m. ET | FOX |
| Colts at Chiefs | Sunday, Sept. 20, 8:20 p.m. ET | NBC/Peacock |
| Giants at Rams | Monday, Sept. 21, 8:15 p.m. ET | ESPN/ABC |
Week 3 follows immediately after, which puts three more slates inside the same 14-day expiry. A $500 or $2,000 deposit earns its keep across that run. A $20 deposit earns its keep tonight.
- $10 to $50, Thursday only. Detroit at Buffalo runs one slate. A $20 deposit plus $10 in bonus funds covers two or three pick'em entries on Josh Allen, Jared Goff, James Cook, and Amon-Ra St. Brown, and the whole balance clears the same night.
- $100, Thursday plus Sunday. $150 total stretches across prime time and the 14-game Sunday slate two days later. This tier suits most first-timers.
- $500, the full 14 days. $750 covers Week 2 and Week 3 with room to sit out a slate after a rough night. Bankroll spread across four or five game days beats one big swing on a single quarterback.
- $2,000, the maximum. $3,000 in the account makes sense for players entering contests every week through early October. Anyone planning a single Thursday session leaves most of that cash idle before the 14-day clock runs out.
How Do You Claim the Underdog Promo Code TOPACTION Offer?
- Tap any Underdog promo code link on this page to open registration.
- Enter promo code TOPACTION during signup.
- Deposit at least $10
- Collect your 50% match, up to $1,000 in bonus funds.
- Enter Keep Your Million before the 8:15 p.m. ET kickoff.
I ran this exact signup on my phone last Thursday and finished in under four minutes.
What Is Keep Your Million on Underdog?
Keep Your Million hands every entrant a $1,000,000 virtual pot and 20 higher-or-lower questions about NFL player stats. A slider sits beneath each question, and you drag it to split the pot between the two answers.
- Money on the correct side survives and becomes your new pot
- Money on the wrong side disappears
- Clear all 20 questions, and you keep the surviving cash as a real payout
- Entry costs nothing, so the downside stops at zero
Lions vs. Bills Example for Thursday Night Football
Picture Thursday night’s question being: Josh Allen, higher or lower than 249.5 passing yards?
| Slider position | On Higher | On Lower | Pot if Allen clears 249.5 |
|---|---|---|---|
| 50/50 (safe) | $500,000 | $500,000 | $500,000 |
| 70/30 (leaning) | $700,000 | $300,000 | $700,000 |
| 100/0 (all-in) | $1,000,000 | $0 | $1,000,000 |
An even split protects half the pot, whatever Allen does. A hard push toward one side keeps more cash alive, though a miss costs far more. Most first-timers start conservative, then press later.
Underdog Promo Code TOPACTION – FAQs
What is the Underdog promo code? The Underdog promo code is TOPACTION. Underdog grants entry into Keep Your Million plus a 50% deposit match up to $1,000 in bonus funds on a first deposit of $10 or more.
How does Keep Your Million pay real money? Answer all 20 questions with cash still in the pot, and Underdog pays the remaining amount as real money.
When do the bonus funds from the Underdog bonus code arrive? Immediately after the qualifying deposit clears. My balance updated within seconds, and I entered contests on the same visit.
Must be 18+ (19+ in AL, NE; 19+ in CO for some games; 21+ in AZ, MA, and VA) and present in a state where Underdog Fantasy operates. Terms apply. Concerned with your play? Call 1-800-MY-RESET or 1-800-GAMBLER or visit www.ncpgambling.org; AZ: 1-800-NEXT-STEP (1-800-639-8783) or text NEXT-STEP to 53342; NY: Call the 24/7 HOPEline at 1-877-8-HOPENY or Text HOPENY (467369).
