A SIM line is a virtual subscription that links a phone number, data allowance, and service plan to a single SIM card. Each line typically costs $15 to $40 per month on major carriers, plus taxes and fees that can add 24% to the bill. Adding a line increases your total monthly cost.
Ready to Compare Plans?
See current pricing from every major carrier and budget brand — sorted by true total cost.
Compare Plans →Free to compare · No credit check to browse · Affiliate-supportedWhat Is a SIM Line?
A SIM line is a virtual subscription that links a phone number, data allowance, and service plan to a single SIM card. Each line represents one active account on a carrier’s network, and it is the unit that carriers charge for on your monthly bill. When you see a plan that says “$40 per line,” that is the cost of one SIM line. A single phone can hold multiple SIM lines (via physical SIM and eSIM), but each line is billed separately.
How SIM Lines Affect Your Bill
Every SIM line adds a recurring monthly access fee to your bill. On major national carriers, postpaid lines range from $15 to $40 per line when part of a multi-line family plan, and $60 to $85 for a single line. Budget providers often charge $25 to $35 per line. Beyond the base fee, every line is subject to federal, state, and local taxes and surcharges. According to the Tax Foundation, the average combined tax rate on wireless services is 24% of the bill. That means a $100 plan with four lines can cost $124 after taxes. Each line also incurs regulatory fees such as the Universal Service Fund contribution, which the FCC sets at roughly 5% of interstate revenue. Carriers pass these costs to consumers per line.
SIM Line vs. Device: Two Separate Costs
A common confusion is that a SIM line includes the phone. It does not. The line is the service subscription; the device is a separate purchase. You can bring your own phone (as long as it is compatible with the carrier’s network) and only pay for the line. Conversely, you can buy a new premium smartphone and pay for it over 24 or 36 months in addition to the line fee. That monthly device installment is separate from the line access fee. For example, a $1,000 phone financed over 24 months adds about $42 per month on top of the line cost. Always check your bill to see whether “device payment” or “installment plan” is a separate line item.
Prepaid vs. Postpaid Lines: Cost Comparison
SIM lines come in two main flavors: prepaid and postpaid. Prepaid lines require upfront payment and typically have lower base fees but may offer fewer perks. Postpaid lines bill at the end of the month and often include bundle discounts, but carry higher taxes and fees. The table below shows typical 2026 ranges for a single line.
| Feature | Postpaid Line | Prepaid Line |
|---|---|---|
| Monthly base fee (single line) | $60–$85 | $25–$45 |
| Taxes & fees (as % of base) | ~24% | ~12% (often included) |
| Typical data cap | Unlimited (throttled after 30–50 GB) | 5–20 GB or unlimited (throttled) |
| Multi-line discount | Yes (up to $20/line) | Rare (usually per-line price) |
For a household of four, postpaid plans often cost $30–$40 per line after discounts, while prepaid remains at $25–$45 per line with no discount. The choice depends on whether you value priority data, international features, and bundled perks (postpaid) or lower upfront cost and no credit check (prepaid).
Tips for Managing Multiple Lines
If you have several people in your household, adding extra SIM lines to a single account can reduce the per-line cost. However, watch for these pitfalls:
- Check for activation fees — Many carriers charge a one-time fee of $30–$40 per new line.
- Understand autopay discounts — Signing up for autopay and paperless billing can save $5–$10 per line each month.
- Review your data usage — Light users may save by switching to a prepaid line with a smaller data allowance rather than paying for unlimited.
- Track line-level taxes — Some states add fees per line; check your bill for “state 911 fee” or “utility surcharge” that are charged per line.
Finally, if you have a device on a payment plan, you cannot simply remove the line without paying off the balance. Plan ahead before adding or dropping lines.