That math is pushing more B2B companies toward inside sales outsourcing: handing off prospecting, lead qualification, and appointment setting to a specialized external partner — whether a US-based agency or a dedicated offshore staffing provider — without carrying the overhead of full-time employees.
This article covers the top inside sales outsourcing options for B2B growth, what makes each one worth considering, and the criteria that should actually drive your decision.
Key Takeaways
- Inside sales outsourcing covers prospecting, lead qualification, and appointment setting — handled by an external team, not internal headcount
- The right model depends on budget, sales cycle complexity, and whether you need full campaign management or a dedicated rep you can direct
- Evaluation criteria should go beyond price — industry fit, team caliber, reporting transparency, and scalability matter more
- Offshore dedicated staffing (like SmartScale360) suits SMBs that want skilled reps at significantly lower cost
- Agency models suit companies that need full campaign execution without managing the rep directly
- Define your KPIs before signing anything — then hold the vendor to them from the start
What Is Inside Sales Outsourcing and Why It Matters for B2B
Inside sales outsourcing means hiring an external partner — a staffing provider or a sales agency — to run all or part of your remote sales motion. That covers outbound prospecting, cold outreach, lead qualification, and appointment setting.
Your internal team handles closing. The external partner fills the top of the funnel.
Why B2B Companies Are Moving Fast on This
The numbers behind SDR hiring tell a consistent story:
- ~3.9 months average ramp time before a new SDR reaches full productivity
- 1.8 years median tenure, meaning most SDRs leave before you've recouped your investment
- 38–50% annual attrition, forcing repeated hiring cycles that drain recruiting budgets and delay pipeline
Add salary to that turnover problem: RepVue data from over 8,500 verified submissions puts SDR on-target earnings around $85,000 — before benefits, equipment, management time, or software seats. For SMBs and growth-stage teams, that's a substantial commitment when pipeline results take quarters to materialize.
Outsourcing converts those fixed hiring costs into a contracted service. The tradeoff is less direct control, but you get a functioning outbound motion in weeks — not quarters.
Top Inside Sales Outsourcing Companies for B2B Growth
Providers below were evaluated on industry experience, service scope, team quality, technology stack, pricing model, and verifiable client results.
SmartScale360
SmartScale360 is a dedicated offshore staffing company with 20+ years of outsourcing experience, connecting US-based B2B businesses with college-educated, English-speaking inside sales professionals from the Philippines. The model is designed specifically for entrepreneurs, SMBs, and multi-industry operators who need skilled inside sales staff without US-level labor costs.
Unlike agency models that pool reps across multiple clients, SmartScale360 places dedicated staff who work exclusively for your business — operating within your CRM, following your sales process, and reporting directly to your team.
Their SDR and inside sales reps are screened for BANT/MEDDIC familiarity and proficiency across:
- HubSpot, Salesforce, and Apollo
- Salesloft and LinkedIn Sales Navigator
- Major appointment-setting and outreach tools
Candidates are pre-vetted for English proficiency and matched to each client's role requirements through a structured three-step consultation and placement process.
| Attribute | Details |
|---|---|
| Best For | SMBs, entrepreneurs, homecare agencies, real estate teams, financial services, law firms, marketing agencies, and franchises needing dedicated inside sales support at reduced cost |
| Key Services | Dedicated offshore inside sales reps, lead generation, appointment setting, CRM and administrative support, scalable staffing |
| Pricing Model | Transparent monthly pricing, no setup fee, no long-term contract |
| Cost Advantage | Up to 60–70% lower labor cost compared to US in-house hires |
Callbox
Callbox has operated since 2004 — over 20 years in B2B lead generation — serving technology, healthcare, SaaS, and B2B services companies globally. Their model combines human SDRs with AI-supported multichannel outreach across email, phone, LinkedIn, and chat.
Their campaign pod structure is well-suited to companies with complex buying groups and longer sales cycles. Callbox publishes case study results including 113 SQLs and 124 MQLs for a GIS software client in six months, with a Clutch rating of 4.6/5 across 119 reviews.
| Attribute | Details |
|---|---|
| Best For | Medical device, technology, and B2B services companies with long or complex sales cycles |
| Key Services | Lead generation, appointment setting, lead nurturing, account-based marketing |
| Pricing Model | ~$15,000–$30,000/month per campaign pod (vendor-published estimate; final quotes vary by scope) |
Martal Group
Martal Group focuses primarily on SaaS, technology, cybersecurity, fintech, and manufacturing — sectors where pipeline qualification demands real sales expertise. Their Sales-as-a-Service model uses senior Sales Executives with 3–5+ years of outbound B2B experience, supported by an AI-powered prospecting platform that monitors intent signals across millions of accounts.
Their published results include 2,316 leads, 1,219 SQLs, and 832 meetings over three years for a financial services client. Clutch rates them 4.8/5 across 109 reviews, with pilots starting at three to four months before moving to monthly subscriptions.
| Attribute | Details |
|---|---|
| Best For | SaaS, technology, and high-growth B2B companies needing fast pipeline ramp with senior outbound expertise |
| Key Services | Outbound lead generation, appointment setting, full-cycle sales outsourcing, AI-powered prospecting |
| Pricing Model | Flat monthly retainer for base tiers; commission added at higher tiers; custom quote required |
CIENCE
CIENCE, founded in 2015, separates its pricing into distinct components — strategy, platform, and SDR capacity — making it one of the more transparent models in the market. Their public pricing lists a $5,000 one-time GTM setup, $2,000/month for the strategic team, and $499/month for their graph8 platform, with optional SDR capacity priced separately.
Their research-first methodology builds highly targeted prospect lists using predictive analytics and AI-driven lead scoring, which suits enterprise and high-growth B2B companies that need targeted account lists over broad spray-and-pray outreach.
| Attribute | Details |
|---|---|
| Best For | B2B tech, SaaS, and enterprise companies seeking data-driven account-based outreach |
| Key Services | Lead generation, appointment setting, ABM, outbound sales development, AI-supported GTM |
| Pricing Model | Itemized managed-service model — setup fee + monthly strategic team fee + platform fee + optional SDR capacity |
Belkins
Belkins has operated since 2017 with a sharp focus on B2B appointment setting and personalized outbound — particularly in hard-to-access industries like SaaS, IT, healthcare, and manufacturing. Their model emphasizes meeting quality over raw volume, combining cold email personalization, LinkedIn outreach, and calling within an account-based framework.
Published results include 341 appointments in eight months and $300K+ in closed revenue for a fire-safety client, and $2.2M in pipeline for Terrascope. Clutch rates them 4.9/5 across 231 reviews — the highest Clutch rating among providers in this list.
| Attribute | Details |
|---|---|
| Best For | SaaS, IT, healthcare, and manufacturing companies needing personalized ABM-driven appointment setting |
| Key Services | Cold email, appointment setting, lead nurturing, ABM, LinkedIn prospecting |
| Pricing Model | Customized monthly retainer; projects commonly reported around $5,500/month on Clutch |
How We Chose These Inside Sales Outsourcing Companies
Providers were assessed across six dimensions:
- Industry experience — depth in specific verticals, not just general B2B claims
- Results transparency — case studies with real metrics (meetings held, SQLs delivered, pipeline), not just logo walls
- Team caliber — seniority of reps, staff-to-client ratios, and whether accounts are staffed with dedicated or shared resources
- Technology and reporting — CRM integration, tracking cadence, and what KPIs are shared with clients
- Pricing flexibility — clear pricing structures and options that scale with client needs
- Scalability — scales up or down without lock-in penalties
The most common mistake buyers make is selecting based on brand polish or lowest price. A provider with a well-designed website and no verifiable client outcomes is a red flag. Prioritize partners who can demonstrate:
- Category-specific results with real numbers attached
- A clear, agreed-upon definition of what counts as a qualified meeting
- A dedicated point of contact who owns your account
Conclusion
There's no single right answer here — the best inside sales outsourcing partner depends on your budget, company size, sales cycle complexity, and what you're actually trying to hand off.
Two models tend to fit different situations:
- US-based agency: Better for companies that need full campaign management and multi-channel execution without directing the day-to-day work
- Dedicated offshore staffing: Better for SMBs and founder-led teams who want a skilled rep working inside their process, logging into their CRM, and reporting directly to their sales lead
Before committing to any provider, assess scalability, reporting transparency, and cultural alignment. Define your KPIs before the engagement starts — meetings booked, SQLs delivered, pipeline generated, revenue influenced — so any partner can be held accountable from day one.
SmartScale360 offers a no-contract, no-setup-fee model with dedicated offshore inside sales professionals matched to your specific business needs. If you're an SMB or founder-led team looking to build pipeline without the overhead of a US hire, contact the SmartScale360 team to see whether dedicated offshore inside sales staffing fits your growth goals.
Frequently Asked Questions
What is outsourcing in sales?
Sales outsourcing means hiring an external company or staffing partner to handle defined parts of the sales process — prospecting, lead qualification, appointment setting — so the internal team can focus on closing and account management.
What is the difference between B2B and inside sales?
B2B refers to the type of transaction — a business selling to another business. Inside sales refers to the method — selling remotely via phone, email, and video rather than in-person field visits. Most B2B companies today use inside sales as their primary sales motion, so the two terms are often used together.
Is outsourcing illegal in the US?
Outsourcing — including hiring offshore staff or third-party agencies — is entirely legal in the US. Companies must follow applicable tax, labor, and data privacy rules, so consult a legal or HR advisor for requirements specific to your industry.
How much does inside sales outsourcing cost?
Costs vary by model. US-based agency retainers typically run $1,000–$25,000+ per month depending on scope and service level. Dedicated offshore staffing models can cut labor costs by up to 60–70% compared to hiring US-based SDRs in-house.
What are the signs it's the right time to outsource inside sales?
Common triggers include:
- Internal reps spend more time prospecting than closing
- Pipeline consistently underperforms against targets
- You're entering a new market and need coverage fast
- Budget doesn't support full-time sales hires
If any of these apply, outsourcing is worth a serious look.
Can I outsource inside sales if I already have an in-house sales team?
Yes — and it often works well. The external team handles top-of-funnel work like prospecting and lead qualification while internal reps focus on high-value conversations, demos, and closing. This setup increases overall team output without adding full-time headcount.
