True cost comparison — not just what the pricing page says
Quick Verdict
Slack saves you 100%
Best for Gusto
Payroll, benefits, and HR platform for small businesses. Base at $40/mo + $6/person/mo, but benefits
Best for Slack
Team messaging and collaboration hub. Free plan has a 90-day message history limit that forces upgra
Payroll, benefits, and HR platform for small businesses. Base at $40/mo + $6/per...
Advertised
$40
/month
True Cost
$136
/month (typical)
Per-Person Fee Scaling
Simple plan: $40/mo + $6/person. Plus: $80/mo + $12/person. Premium: $180/mo + $22/person. A 25-pers...
Benefits Administration Add-On
Health insurance, 401(k), and benefits administration are not included in Simple. Plus plan ($80/mo ...
State Tax Registration Fees
Registering for state taxes in new states costs $35-$100 per state as a one-time fee. Multi-state re...
Team messaging and collaboration hub. Free plan has a 90-day message history lim...
Advertised
$0
/month
True Cost
$8
/month (typical)
90-Day Message History Limit
Free plan deletes message access after 90 days. Your team's entire knowledge base disappears quarter...
Per-User Cost at Scale
A 100-person company on Pro pays $875/mo ($10,500/yr). Business+ is $1,250/mo ($15,000/yr). The per-...
Slack Connect External Channels
Connecting with external organizations requires Pro ($8.75/user/mo) minimum. Free plan has no extern...
$7/mo annual
Gusto advertises $40/mo. Slack advertises $0/mo.
Gusto has 3 documented hidden fees. Slack has 3.
Gusto confidence: 76%. Slack confidence: 83%.
| Metric | Gusto | Slack | Winner |
|---|---|---|---|
| Advertised Price | $40/mo | $0/mo | Slack |
| True Monthly Cost | $136/mo | $8/mo | Slack |
| Hidden Fee Total | +$96/mo | +$8/mo | Slack |
| # Hidden Fees | 3 | 3 | Gusto |
| Confidence Score | 76% | 83% | Slack |
| Pricing Tiers | 3 | 4 | — |
| Affiliate Program | None | No public affiliate program | — |
Gusto advertises $40/mo and Slack advertises $0/mo. However, when you include hidden fees, Gusto has 3 documented hidden fees adding +$96/mo, while Slack has 3 hidden fees adding +$8/mo. Based on true cost, Slack is typically 100% cheaper.
Gusto has 3 documented hidden fees: Per-Person Fee Scaling, Benefits Administration Add-On, State Tax Registration Fees. These add approximately +$96/mo on top of the $40/mo advertised price.
Slack has 3 documented hidden fees: 90-Day Message History Limit, Per-User Cost at Scale, Slack Connect External Channels. These add approximately +$8/mo on top of the $0/mo advertised price.
Choose Gusto if: Payroll, benefits, and HR platform for small businesses. Base at $40/mo + $6/person/mo, but benefits. Choose Slack if: Team messaging and collaboration hub. Free plan has a 90-day message history limit that forces upgra. The right choice depends on your team size, usage volume, and which features you need most.
This comparison is based on manual research of official pricing pages, terms of service, and user reports. Gusto data has a 76% confidence score and Slack has 83%. Prices were last verified in April 2026. For the most accurate estimate, enter your specific usage in our calculator.
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