Best Prepaid Cell Phone Plans for Families of 3 to 4 Lines Under $100 per Month

Paying for three or four phone lines can feel like you are stuck. The plan looks affordable, then the bill climbs with fees, add-ons, and “just this once” charges.

Prepaid plans can fix that. You pay upfront each month (or year), you avoid contracts, and you can pick exactly the amount of data your family needs.

This guide focuses on one goal: Best Prepaid Cell Phone Plans for Families of 3 to 4 Lines Under $100 per Month, using only these assigned brands: AT&T, T-Mobile, US Mobile.

At-a-glance comparison table (3 to 4 lines under $100)

Brand	Plan	3 lines total	4 lines total	Data style	Best for
T-Mobile	T-Mobile Prepaid “4 lines for $100”	Usually not the best fit for 3 lines	$100	Capped high-speed data per line	Families that want a clean, fixed 4-line price
T-Mobile	Connect by T-Mobile ($15 tier)	$45 + tax	$60 + tax	5GB per line	Light-data families who live on Wi-Fi
US Mobile	Unlimited Starter	$67.50	$90	Unlimited plan with typical “fair use” terms	Families who want flexibility and value
AT&T	12-month prepaid (annual)	$60 equiv.	$80 equiv.	16GB high-speed then slower	Families who can pay upfront and want AT&T

Note: Some plans add taxes and fees on top of the advertised price. Always confirm the final total in your cart, and check the plan’s “Broadband Facts” label when available.

How to choose a prepaid family plan under $100

Start with data reality, not marketing

Most families overpay because they buy the same “big” plan for every line.

Do this instead:

• Check each phone’s data use for the last 30 days.
• Circle the two highest users.
• Build the plan around them, then keep the other lines cheaper.

Simple data guide (per line):

Monthly data use	What it feels like	Plan style that fits
0 to 5GB	Mostly Wi-Fi, light video	Low-cost capped data
6 to 12GB	Mixed Wi-Fi and cellular	Mid-tier capped data, or value unlimited
13GB+	Lots of streaming off Wi-Fi	Unlimited is easier

Look for a “family proof” price

A family plan should stay predictable when someone watches a little extra video.

Two common pitfalls:

• A low price that jumps after the first month
• A plan that is cheap until you add hotspot or extra data

Your goal is boring billing. Boring is good.

Hotspot can be the hidden deal breaker

Hotspot is what saves you during travel, school events, or home internet outages.

Ask three questions before you buy:

• Is hotspot included?
• How much hotspot data is included?
• What happens after the high-speed bucket runs out?

Connect by T-Mobile is very clear that each plan includes a set amount of high-speed data, and once you reach the limit, on-network data ends until the next billing date (unless you add a pass or change plans).

AT&T’s annual plan includes 10GB of hotspot data, with high-speed data up to a set amount, then slower speeds after that.

US Mobile lists Unlimited Starter with unlimited talk and text plus plan features and pricing that keep a 4-line family under $100.

Coverage is about your life, not a map screenshot

A “good network” is not helpful if your parent commute or your kids’ school has dead spots.

Use this fast method:

1. Write down 5 places you must have service (home, work, school, gym, grandma’s house).
2. Ask a neighbor or coworker what works there.
3. Pick the brand that matches your real-world locations.

A 2-minute family math worksheet (use this before you decide)

Your family profile	What usually wins under $100	Why it works
4 lines, moderate data, want one fixed number	T-Mobile Prepaid 4 lines for $100	Straightforward cap and price
4 lines, need margin under $100	US Mobile Unlimited Starter	Under $100 with room to spare
3 to 4 lines, mostly on Wi-Fi	Connect by T-Mobile $15 tier	Lowest cost, clear caps
3 to 4 lines, can pay upfront	AT&T 12-month	Lowest “monthly equivalent” for AT&T

Best options by brand (AT&T, T-Mobile, US Mobile)

T-Mobile: Best for a clean 4-line price, or ultra-budget capped lines

Best T-Mobile pick for a 4-line family under $100: T-Mobile Prepaid “4 lines for $100”

If your household is exactly four lines and you want a firm price target, this plan is built for you.

What you get, at a high level:

• 4 lines for $100 per month
• 10GB of high-speed data per line
• Hotspot use tied to your data bucket

Who it is for: families that want a fixed, easy monthly number, and are okay with a defined data cap per line.

Who should skip it: families with three lines, or families where two people regularly burn through more than 10GB.

Best T-Mobile pick for light users: Connect by T-Mobile

Connect is the “control the bill” choice.

Key details that matter for families:

• $15 plan includes 5GB
• $25 plan includes 8GB
• $35 plan includes 12GB
• When you hit the limit, on-network data service ends until the next billing date (unless you add a pass or switch plans)

Real family cost examples (before tax):

• 4 lines on $15: $60
• 3 lines on $15: $45
• Mixed setup: 2 lines on $25 plus 2 lines on $15 = $80

That mixed setup is a smart family move. Parents get more data, kids get cheaper lines.

Best use case: kids and grandparents who use Wi-Fi most of the time.

Big downside: hard cutoff on data can be frustrating for a teenager who forgets Wi-Fi.

US Mobile: Best for value and flexibility under $100

Best US Mobile pick for families: Unlimited Starter

If you want 4 lines under $100 and you also want flexibility, this is the easiest math in the guide.

Pricing math:

• $22.50 per line per month
• 3 lines = $67.50
• 4 lines = $90

Why families like it:

• It stays under $100 with room left.
• It is simpler than building four different capped plans.
• It fits families with mixed data habits.

What to watch:
Even “unlimited” plans can have terms that reduce speeds after very high use, especially during congestion. That is normal across the industry.

When US Mobile makes the most sense

Choose US Mobile if you want any of these:

• A cushion under $100 so taxes or add-ons do not break the budget
• A plan that works even if a kid starts using more data later
• An easy setup that does not require constant monitoring

AT&T: Best if you can pay upfront and want AT&T coverage

Best AT&T pick under $100: the 12-month prepaid plan (annual)

This is the “lower monthly equivalent” option.

The deal, in plain terms:

• Pay $240 today
• Get 12 months of unlimited talk, text, and data
• Includes 10GB hotspot
• After 16GB, speeds slow to a max of 1.5 Mbps

Family cost, monthly equivalent:

• 3 lines: $60 per month equivalent
• 4 lines: $80 per month equivalent

Who it is for: families that can handle a bigger upfront payment and want the AT&T option while staying comfortably under $100.

Who should skip it: anyone who cannot pay upfront, or anyone who needs consistent high-speed data beyond the high-speed amount.

People Also Asked, fast answers for families

Can you really get 4 lines under $100 on prepaid?

Yes. T-Mobile Prepaid has a specific 4-lines-for-$100 offer, and US Mobile Unlimited Starter stays under $100 for four lines.

Is prepaid a good idea for kids’ lines?

Usually, yes. Prepaid is great for budget control, and capped-data plans can prevent surprise overuse. Connect is a strong option for this style.

How do I avoid “hidden fees” when comparing plans?

Look for the plan’s Broadband Facts label, or the official plan disclosure, and confirm whether taxes and fees are included. The FCC broadband labels are designed to help consumers compare pricing, data allowances, and speeds more easily.

What is the easiest plan for a family that hates managing data?

US Mobile Unlimited Starter is the simplest under-$100 option, because 4 lines stays below the cap with breathing room.

What is the cheapest setup for 4 lines under $100?

If your family uses mostly Wi-Fi, Connect by T-Mobile at $15 per line is the lowest monthly price, before tax.

The best choice, based on your family’s habits

If you want a decision in one minute:

• Pick T-Mobile Prepaid 4 lines for $100 if your family is exactly four lines and most people can live with a 10GB cap.
• Pick US Mobile Unlimited Starter if you want to stay under $100 with room left, and you do not want to micromanage data.
• Pick Connect by T-Mobile if your family lives on Wi-Fi and you want the lowest monthly bill possible.
• Pick AT&T 12-month prepaid if you can pay upfront and you want an AT&T option well under $100.

This is also why the keyword matters. Best Prepaid Cell Phone Plans for Families of 3 to 4 Lines Under $100 per Month is less about finding one perfect plan, and more about matching the plan to how your family really uses data.

Conclusion

You can absolutely hit Best Prepaid Cell Phone Plans for Families of 3 to 4 Lines Under $100 per Month today with AT&T, T-Mobile, or US Mobile.

The winning strategy is simple:

1. Check data use for each line.
2. Decide if you want fixed price simplicity, or the lowest possible monthly bill.
3. Choose the plan that fits your real habits, then stick with it.

If you want the safest under-$100 play for most families, US Mobile Unlimited Starter is the easiest “no stress” option. If you want a strict, fixed 4-line price, T-Mobile Prepaid 4 lines for $100 is the cleanest match. If you use Wi-Fi everywhere, Connect is the budget champion. If you can pay upfront, AT&T’s annual plan can cut your monthly equivalent cost a lot.

The responses below are not provided, commissioned, reviewed, approved, or otherwise endorsed by any financial entity or advertiser. It is not the advertiser’s responsibility to ensure all posts and/or questions are answered.