Best WHMCS Addons, Modules and Developers: A Buyer's Guide
No single WHMCS addon is best. This buyer's guide sorts modules by job, names the vendors and module developers behind them, and gives a checklist to run before you pay.
Guides from client work
Step-by-step guides written from my own client work and checked against the official documentation. Each one says when it was last reviewed, and what I sell when it matters.
Editor's pick
No single WHMCS addon is best. This buyer's guide sorts modules by job, names the vendors and module developers behind them, and gives a checklist to run before you pay.
Latest articles
11 min
The three bills behind a WhatsApp AI chatbot: the build, Meta's per-message fees with US, UK and EU rates, and AI model usage, worked through for one month.
12 min
A working method for your first freelance client as a developer: the five routes first clients come from, the proof buyers check, how to size and price the first job, what to put in writing, and when to walk away.
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A checklist for an AI-ready website: crawler access, the newer Search Console and Cloudflare AI settings, pages AI can read, forms agents can use, and how to measure it.
12 min
ZDI-CAN-33367, the skb_zerocopy Linux kernel zero-day, for hosting teams: who is exposed, the one-line check, the mitigation and what it breaks, and the fixed kernels and livepatches to install.
11 min
The Upwork Top Rated requirements, taken from Upwork's help center: the eight criteria, the Rising Talent shortcut, how the Job Success Score is calculated daily, and what makes a badge disappear.
11 min
How to set up DMARC under the new RFC 9989: inventory senders, align SPF and DKIM, publish p=none with reports, read them, then move to quarantine and reject. Includes Google Workspace, Microsoft 365 and cPanel notes.
12 min
The real Fiverr Top Rated seller requirements, from Fiverr's help center: the six metrics, the manual review, priority review categories, how status lasts, and how it compares with Upwork's badges.
12 min
How to add a WHMCS dark mode: what Twenty-One, Nexus and the order forms offer today, a child theme with CSS variables, a toggle that remembers the choice, contrast checks and when a ready-made dark theme fits.
11 min
A RAG chatbot looks up your own documents before it answers. I explain each step in plain words, when fine-tuning or a long prompt fits better, why RAG answers go wrong, and what to ask about data and cost.
11 min
What a WHMCS MCP server does, the Marketplace modules, open-source packages and hosted service that exist today, which WHMCS API actions to expose first, and a safety model built on API roles, approvals and audit logs.
11 min
How to set up tax in WHMCS 9.1 for UK VAT, EU VAT, Australian GST and US state sales tax: tax rules, inclusive or exclusive prices, VAT number checks, paid invoice numbering and launch checks.
11 min
A dated comparison of the vibe coding tools people use: browser app builders versus coding agents, entry plan prices from each vendor's own page, what you can export, and when to bring in a developer.
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