True cost comparison — not just what the pricing page says
Quick Verdict
Klaviyo saves you 100%
Best for Microsoft 365
E-commerce email and SMS marketing platform. Free for 250 contacts, then contact-based pricing that
Best for Klaviyo
Microsoft's business productivity suite (Outlook, Teams, Office apps). Per-user pricing where deskto
Microsoft's business productivity suite (Outlook, Teams, Office apps). Per-user ...
Advertised
$6
/month
True Cost
$114
/month (typical)
Desktop Apps Require Business Standard
Business Basic ($6/user/mo) only includes web and mobile Office apps. Desktop Word, Excel, PowerPoin...
Copilot AI Add-On
Microsoft 365 Copilot AI is $30/user/mo — separate from all base plans. For 50 users, Copilot alone ...
Compliance Features Require E5
Advanced compliance (eDiscovery, DLP, Information Barriers, Insider Risk Management) require Enterpr...
Teams Phone Add-On
Microsoft Teams Phone System for PSTN calling is not included in any standard plan. Teams Phone Stan...
E-commerce email and SMS marketing platform. Free for 250 contacts, then contact...
Advertised
$0
/month
True Cost
$205
/month (typical)
Steep Contact-Based Scaling
Free for 250 contacts. Then: 1K = $30/mo, 5K = $100/mo, 10K = $150/mo, 25K = $400/mo, 50K = $720/mo....
SMS Credits Charged Separately
SMS marketing requires separate credit purchases. US SMS: $0.01-$0.015/message. 10K SMS/mo = $100-15...
Email Send Limits Per Tier
Email sends are capped at 10x your contact limit on most plans. Exceeding requires upgrading to a hi...
Klaviyo advertises $0/mo. Microsoft 365 advertises $6/mo.
Klaviyo has 3 documented hidden fees. Microsoft 365 has 4.
Klaviyo confidence: 78%. Microsoft 365 confidence: 84%.
| Metric | Microsoft 365 | Klaviyo | Winner |
|---|---|---|---|
| Advertised Price | $6/mo | $0/mo | Klaviyo |
| True Monthly Cost | $114/mo | $205/mo | Microsoft 365 |
| Hidden Fee Total | +$107.5/mo | +$205/mo | Microsoft 365 |
| # Hidden Fees | 4 | 3 | Klaviyo |
| Confidence Score | 84% | 78% | Microsoft 365 |
| Pricing Tiers | 3 | 3 | — |
| Affiliate Program | No public affiliate program | None | — |
Microsoft 365 advertises $6/mo and Klaviyo advertises $0/mo. However, when you include hidden fees, Microsoft 365 has 4 documented hidden fees adding +$107.5/mo, while Klaviyo has 3 hidden fees adding +$205/mo. Based on true cost, Klaviyo is typically 100% cheaper.
Microsoft 365 has 4 documented hidden fees: Desktop Apps Require Business Standard, Copilot AI Add-On, Compliance Features Require E5, Teams Phone Add-On. These add approximately +$107.5/mo on top of the $6/mo advertised price.
Klaviyo has 3 documented hidden fees: Steep Contact-Based Scaling, SMS Credits Charged Separately, Email Send Limits Per Tier. These add approximately +$205/mo on top of the $0/mo advertised price.
Choose Microsoft 365 if: E-commerce email and SMS marketing platform. Free for 250 contacts, then contact-based pricing that . Choose Klaviyo if: Microsoft's business productivity suite (Outlook, Teams, Office apps). Per-user pricing where deskto. 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. Microsoft 365 data has a 84% confidence score and Klaviyo has 78%. Prices were last verified in April 2026. For the most accurate estimate, enter your specific usage in our calculator.
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