What is a B2B customer search tool (lead generation)?
It is software that helps find businesses and the right decision-makers, enrich information (email, phone number, title), then send automated outreach sequences; some add AI to write emails or find buying signals. For a solo agency, five commonly mentioned tools are Apollo, Hunter, Clay, Instantly and Lemlist. I need to say upfront two things: the prices listed below are only the tool costs, not including the time you spend writing emails and handling responses; and the contact databases of these tools are mainly oriented toward international markets, and we have not verified their coverage of Vietnamese businesses. This post describes each tool based on official pricing pages as of 24/10/2026, how to choose, and legal notes in Vietnam.
Finding and sending tools are only half the story; the other half is the right message and legal sending. Diagram: OPCAIOS.
What steps does a B2B customer search process involve?
A B2B customer search process is a chain of five steps from selecting a customer group to tracking responses; tools only support each step, while the right message is still your work. First, narrow down your customer group; next, find and verify the list; then send a short sequence; finally, feed responses into a CRM like HubSpot or Pipedrive. Details:
- Choose your customer group and their problem (see 30-Day Roadmap to Building an OPC).
- Find a list (companies, decision-makers).
- Enrich and verify emails to reduce bounce-backs.
- Send a short outreach sequence with real personalization, including an opt-out method.
- Track responses and feed into a CRM (see What is HubSpot?, What is Pipedrive?).
How much do Apollo, Hunter and Clay cost?
Apollo, Hunter and Clay are three tools focused on finding and enriching contact data. Prices are in USD, read from official pages on 24/10/2026, before tax, subject to change:
| Tool | Role | Free plan | Typical paid price |
|---|---|---|---|
| Apollo | Contact database and outreach sequences | Yes (limited Gmail email connections) | Page does not list specific prices in the section we read; Basic, Professional, Custom plans; annual commitment gets discount |
| Hunter | Find and verify emails | 50 credit per month, 1 email account | Starter $49 ($34 if paid annually), 2,000 credit; Growth $149 ($104), 10,000 credit; Scale $299 ($209), 25,000 credit |
| Clay | Enrich data from multiple sources, automate | Yes: 500 actions and 100 data credit per month, max 200 rows per table | Launch $167 per month (FAQ says $185), 15,000 actions; Growth $446 (FAQ says $495) |
Clay prices differ between the pricing table and FAQ, so check before paying. Hunter credit does not roll over to the next month (per their page). Example: a solo agency wanting to try 50 contacts could start with Hunter's free plan (50 credit per month) before spending $49 on Starter.
How much do Instantly and Lemlist cost?
Instantly and Lemlist are two tools focused on sending outreach sequences. Prices are in USD, read on 24/10/2026, before tax:
| Tool | Role | Free plan | Typical paid price |
|---|---|---|---|
| Instantly | Send large-scale outreach sequences, warm up mailboxes | None visible on page | Growth $47 ($37.60 if paid annually), 5,000 emails per month, 1,000 contacts to upload; Hypergrowth $97 ($77.60); Light Speed $358 ($286.30); find credits sold separately (from $47 per month for 1,500 credit) |
| Lemlist | Multi-channel outreach (email, LinkedIn, calls) | None visible on page | Email $55 per month (paid annually) or $69, 50,000 emails; Multichannel $87 or $109; add data $20 per month for 2,000 credit |
With Instantly, the email count for the Hypergrowth plan differs between the pricing card and comparison table, so double-check before paying. Example: sending a short sequence to a few hundred contacts per month fits within the 5,000 email limit of the Growth plan at $47; if you need LinkedIn or calls too, check out Lemlist Multichannel at $87.
Which tool should a solo agency choose?
You should choose based on priorities. We don't rank them because we haven't tried all of them; the table below is just a suggestion based on official pricing pages.
| Priority | Suggestion |
|---|---|
| Start cheap, try small | Hunter or Apollo free plan to find and verify a few dozen contacts |
| Want deep personalization with data from many sources | Clay, accepting complexity and higher cost |
| Send large volumes from multiple mailboxes | Instantly, with responsibility for mailbox deliverability |
| Multi-channel reach (LinkedIn, calls) | Lemlist Multichannel plan |
| Clients mainly in Vietnam | Check sample data before paying; often a warm network and effective content work better than tools |
Legal and reputation notes
- Consent and opt-out: Decree 91/2020/NĐ-CP (effective 1/10/2020) regulates against spam messages, emails and calls; according to news articles, sending ads without consent or after someone has opted out can result in fines (reportedly 5 to 10 million đồng); this information comes from news sources and hasn't been cross-checked against the original text, and there are draft changes; ask a legal expert. Always provide a way to opt out and respect opt-out requests.
- Personal data: collecting, storing and using personal emails and phone numbers requires a legal basis; ask an expert.
- Domain reputation: bulk sending easily flags a domain as spam; use a dedicated domain for outreach, ramp up gradually, authenticate SPF, DKIM, DMARC (see What is email marketing? and What is Brevo? on responsible email sending).
- Don't make false claims: outreach emails shouldn't promise beyond your ability.
- Tool terms: many platforms ban spam; violating this can get your account locked.
OPCAIOS experience
We don't use all five of these tools; our system has a custom-built CRM, customers come from forms, diagnostic quizzes and booking links, and rules that exclude opted-out people from automated emails. We haven't run large-scale cold outreach campaigns and don't have response rate numbers for each tool. What we believe: for a solo agency, a small, right-fit list and genuinely personalized emails usually beat sending to many.
Read more: "Cold Outreach without spam" techniques.
Frequently asked questions
Which tool is best for finding B2B customers?
No tool is best for every agency, and OPCAIOS doesn't rank because we haven't tried all five. Based on official pricing pages checked on 24/10/2026, each tool serves a different role. Hunter and Apollo are good to start because they have free plans (Hunter 50 credits per month). Clay is good when you need to enrich data from many sources, with Launch plan $167 per month. Instantly (Growth $47) and Lemlist (Email $55 when paid annually) are good when you need to send outreach sequences. For example, a new agency could use Hunter to verify 50 emails first, then pay for a sending tool. What matters more than the tool is choosing the right customers and writing truly personalized emails.
Are there free tools?
Yes, three of the five tools have free plans according to pricing pages checked on 24/10/2026: Hunter (50 credits per month), Apollo (limited email finding for Gmail) and Clay (500 actions, 100 data credits per month). Instantly and Lemlist pricing pages don't show free plans. Free plans are enough to test the process, but bulk sending requires a paid tool.
Is cold email outreach legal in Vietnam?
It depends on how you send it, and this isn't legal advice. Decree 91/2020/NĐ-CP regulates against spam messages, emails and calls. According to news articles, sending ads without consent or after someone has opted out can result in fines of 5 to 10 million đồng; this information hasn't been cross-checked against the original text and there are draft changes. Always provide a way to opt out, respect opt-out requests and ask a legal expert before sending at scale.
Does the database cover Vietnamese businesses?
We haven't verified; ask for sample data or try the free plan before paying.
How should I start?
Pick a narrow customer segment, find 30 to 50 contacts, send a short sequence with genuine personalization, measure responses. To learn how to build a customer-finding process with AI, see OPCAIOS's AI application training course.
Source: official pricing pages of Apollo, Hunter, Clay, Instantly, Lemlist, checked on 24/10/2026, and search results on Decree 91/2020/NĐ-CP (not cross-checked against original text). Prices exclude tax and may change; some pages have inconsistent data as noted. Experience is OPCAIOS's.
Translated from Vietnamese with AI. Read the original.
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