📍 16 East 40th St, Midtown Manhattan
get@callifi.com
If your callers get busy signals or your team waits to dial out, you don't have enough lines. If you're paying for lines you don't use, you have too many. Here's how to figure it out.
For decades, businesses asked their phone company: "How many lines do we need?" The answer mattered because each analog phone line was a separate copper wire from the central office, a separate monthly charge, and a hard limit on simultaneous calls.
If you have 4 lines and 5 people try to dial out at the same time, the 5th person gets a busy signal. If 4 people are talking and a customer calls in, they hear a busy signal too — they hang up and call your competitor.
With VoIP, this question changes. There are no physical "lines" — calls travel over your internet connection. But the underlying question remains: how many simultaneous calls can your system handle? Here's how to figure it out for your business.
You don't need a line for every employee. You need enough capacity for your highest-volume moment. A 30-person office where only 8 people are typically on the phone at any given time needs about 10-12 simultaneous call slots, not 30.
To estimate this, observe your office for a few days. Count peak concurrent calls during your busiest hour — usually mid-morning for B2B or mid-afternoon for consumer-facing businesses. Add 20-30% buffer for unusual peaks. That's your minimum capacity.
If your business does heavy inbound (medical offices, customer support, real estate brokerages), you need more capacity than your outbound calls suggest. A medical office with 6 staff might have 8 inbound calls coming in simultaneously during morning rush — even if only 3 staff are actively talking.
If your business does heavy outbound (sales teams, collections), you need capacity for everyone who needs to dial out at once.
Each line is a hard cost: $30-60/month from your carrier. You buy exactly the number of lines you need, no more. Adding lines takes 1-3 weeks for the carrier to provision. Sizing rule: count peak simultaneous calls + 20% buffer. Skimping costs you missed calls; over-provisioning costs you money every month.
SIP trunks deliver virtual lines over your internet to your existing PBX. Pricing is per "channel" (simultaneous call). More flexible than analog — you can add or remove channels in days, not weeks. Sizing rule: peak simultaneous calls + 20% buffer, with the freedom to scale up during busy seasons.
With hosted VoIP, the question of "lines" is replaced by per-user pricing. Each user gets unlimited simultaneous calls — typically 2-3 calls per user can be active at once (e.g., one active call, one on hold, one on a transfer). For a 30-user office, that's effectively 60-90 possible simultaneous call slots. Sizing rule: count users, not lines. Most businesses never hit a capacity limit.
Hosted VoIP with one user license per employee. No "line" sizing needed — capacity is more than sufficient. Typical cost is per-user monthly with everything included.
Same: hosted VoIP per user. The complexity isn't capacity — it's call routing, ring groups, departments, and after-hours rules.
Hosted VoIP per agent + queueing for callers in busy periods. The bottleneck isn't lines, it's agents — making sure callers don't wait too long to reach a person.
Count peaks, add buffer, plus reserve a line or two for fax and elevator phone if those are still on copper. As lines fail and carriers stop servicing copper, plan migration to SIP trunks or hosted VoIP.
For most NYC businesses, the answer is to stop thinking in "lines" and switch to a per-user hosted VoIP plan that gives you unlimited simultaneous calls. The cost is comparable to what you're paying for analog lines plus maintenance, and capacity is no longer a concern.
If you want to know what your business actually needs, schedule a free assessment. We'll observe your call patterns, look at your current setup, and recommend the right capacity. Or call (212) 423-1234.
