More sustainable than new

Galaxy S21 Ultra 5G 128GB - Black - Locked AT&T - Dual-SIM

1 / 3.
Affirm
Buy now, pay later.

Free delivery
Only compatible with
AT&T

Comes with

Charging cable

Get this for even less
Assessment takes 2 minutes and you’ll get an offer instantly. If the price is right, settle up your cart to make it official.
Like starting from . We’ll buy back your old tech for cash.

Accepts

Galaxy S21 Ultra 5G - Locked AT&T's customer reviews

4.5/5

5 verified reviews in the last 6 months.

  • E

    Eric H.

    Purchased on February 18, 2024

    4.9/5

    This is my 3rd purchase from backmartket and I must say, they have never failed to deliver a quality product to me! This phone is in amazing condition it has 1 tiny little scuff on the screen that was maybe ⅛ of an inch long that was super shallow and completely disappeared when I put a screen protector on it!everything else works perfectly and it is a major improvement from my s10 thank your again backmartket I've recommended you to everyone that's said they needed a new phone and plan on purchasing all my tech from you in the foreseeable future if possible

    Reviewed in the United States on March 5, 2024

    Galaxy S21 Ultra 5G 128GB - Black - Locked AT&T - Dual-SIM
  • J

    Jesse V.

    Purchased on February 26, 2024

    5/5

    fast delivery phone as it should be fast trade in payout 3rd time using back market!! never go back! Great savings love it!!

    Reviewed in the United States on March 16, 2024

    Galaxy S21 Ultra 5G 128GB - Black - Locked AT&T - Dual-SIM
  • C

    Charles H.

    Purchased on February 27, 2024

    4.5/5

    just received my phone yesterday and I would order again this place is great I will never buy a new phone again I will buy a used from back market

    Reviewed in the United States on March 2, 2024

    Galaxy S21 Ultra 5G 128GB - Black - Locked AT&T - Dual-SIM
  • M

    Michael P.

    Purchased on February 3, 2024

    4.9/5

    Phone came in early, bought the excellent version. Very few noticeable blemishes. Works as intended. No issues so far. Would definitely recommend.

    Reviewed in the United States on February 18, 2024

    Galaxy S21 Ultra 5G 128GB - Black - Locked AT&T - Dual-SIM
  • L

    Leslie C.

    Purchased on April 9, 2024

    3/5

    El teléfono no esta desbloqueado. y encima esta con AT& T piden $100 pára hacer el desbloqueo, y en la descripcion del equipo dice que esta desbloqueado. No son especificos con lo que describen.

    Reviewed in the United States on July 1, 2024

    Galaxy S21 Ultra 5G 128GB - Black - Locked AT&T - Dual-SIM
See all 5 reviews

Reborn vs. brand new

Here’s what you help prevent on average by choosing a reborn smartphone over a brand new one.

171.1 lbs of CO2e

That's like driving an SUV from NYC to Chicago.

6.3 oz of e-waste

That’s around the weight of a baseball.

537.1 lbs of raw materials

That's like 20 dogs digging in your yard for a week.

20,341.2 gallons of water

That's like running a faucet for 3 days

Everything you ever wanted to know about the Galaxy S21 Ultra 5G - Locked AT&T

The item in this listing is an Open Box (packaging maybe slightly distressed). The unit powers on with factory settings restored and includes the original accessories. The unit may have some minor cosmetic marks. Product comes with a Minimum 90 days warranty

  • • This device is locked to AT&T only and not compatible with any other carrier.
  • • Pro Grade Camera: Zoom in close, take photos and videos like a pro, and capture incredible share-ready moments with our easy-to-use, multi lens camera
  • • Sharp 8K Video: Capture your life’s best moments in head-turning, super-smooth 8K video that gives your movies that cinema-style quality Multiple Ways to Record: Create share-ready videos and GIFs on the spot with multi-cam recording and automatic professional-style effects
  • • 100x Zoom: Get amazing clarity with a dual lens combo of 3x and 10x optical zoom, or go even further with our revolutionary 100x Space Zoom
  • • All Day Intelligent Battery: Intuitively manages your cellphone’s usage to conserve energy, so you can go all day without charging (based on average battery life under typical usage conditions)

Galaxy S21 Ultra 5G 128GB - Black - Locked AT&T - Dual-SIM

  • Color : Black
  • Screen size (inches) : 6.8
  • Model : Galaxy S21 Ultra 5G
  • OS : Android
  • Resolution : 1440x3200
  • Carrier compatibility : AT&T
  • Storage : 128 GB
  • Memory : 12 GB
  • Network : 5G
  • Double SIM : Yes
  • Manufacturer Ref. : SM-G998U
  • Memory Card Slot : No
  • Verizon compatible : No
  • AT&T compatible : Yes
  • T-Mobile compatible : No
  • Release Year : 2021
  • Foldable : No
  • SAR head : 0.77
  • Series : Samsung Galaxy S
  • SIM card : Dual-SIM + eSIM
  • Color (official name) : Phantom Black
  • Product type : Refurbished
  • Brand : Samsung
  • Weight : 8 oz

Welcome to Back Market

The best prices for high-quality reborn tech by sellers we’ve checked and vetted. We don’t mind if you Google us.

Get to know us
  • 1-year warranty
  • Free standard shipping
  • Free 30-day returns
  • Friendly customer service
1 / 3.