VoIP Billing for Resellers: How to Invoice Voice
Tom Reed · Updated 8 November 2026
VoIP billing for a reseller is how you invoice your own customers for the voice service you sell: usually per seat, sometimes with usage, often by passing through what your SIP carrier charges for numbers and outside calls. SessionTalk bills your partner organisation for each SessionPBX customer subscription; you set your own price and invoice the customer, with no commissions or payouts to wait for. SessionPBX is a multi-tenant PBX you can run on your own servers, or SessionTalk can host it, and your customers' users place calls on SessionTalk softphones for Windows, macOS, iOS and Android.
This guide is for MSPs, ITSPs, VoIP providers and IT resellers who resell SessionPBX and need a clean way to bill voice. It covers invoicing mechanics only: who bills whom, and how the customer invoice is structured. Deciding the number on that invoice is a separate job, covered in how to set your VoIP price as an MSP.
What is VoIP billing for a reseller?
When you resell hosted voice, VoIP billing is not one invoice and it is not a billing-software product. It is three invoices that sit on top of each other. Your SIP carrier bills for numbers and external calls. SessionTalk bills your partner organisation for the SessionPBX subscription. You invoice your customer at your own price and on your own terms. The wider name for that stack is telecom billing, and the same idea applies whether you sell to a handful of offices or a long list of small businesses.
The pricing post decides the number on the invoice; this post decides what the invoice is made of. If you are still standing up voice as a line of business, the platform, carrier, apps, support and billing steps are laid out in how to start a VoIP business as an MSP or ITSP. Here we go deep on the billing step only.
Billing is also what separates reselling from referring. A reseller invoices the customer; a referral agent does not. If you are still choosing between those models, read VoIP reseller vs referral agent models first.
Who bills whom when you resell SessionPBX?
| Invoice | From | To | What it covers |
|---|---|---|---|
| Carrier | The SIP-compliant carrier on the trunk you connect | The account holder for that trunk (usually you) | Numbers and external call charges |
| Platform | SessionTalk | Your partner organisation | Each customer subscription. Hosted: monthly or annual. Self-hosted: annual licences |
| Customer | You | Your customer | Hosted voice at your own price and terms. No commissions or payouts |
The end customer pays you. They should never be pointed at SessionTalk for their bill, and SessionTalk does not pay you a commission on what you sell. You create and own each customer's SessionPBX project, so the commercial relationship stays with you from the first invoice onwards.
That split keeps the conversation simple. Your customer sees one supplier for voice: you. You see two upstream bills: the carrier for numbers and calls, and SessionTalk for the platform. How you bundle those into products and tiers is covered in hosted PBX packaging for MSPs and telecom resellers; this guide stays on the invoice itself.
How do you invoice per seat?
A per-seat line is the natural base for a SessionPBX customer invoice, because SessionTalk bills you per seat for the seats you sell, hosted or self-hosted. Self-hosted partners run many customer tenants on their own server, with every customer kept separate and priced per seat. Charging your customer per user lines your revenue up with your own platform bill.
Each billed seat is a person using the apps. Point new customers at the softphone apps your customers' users run, and use rolling out desktop softphones when you plan the first wave of installs. Users set up by QR code or desktop link, so the seat count on your invoice should match the people who actually scanned in. Keep that list tidy with the provisioning patterns in provisioning softphones securely: when someone leaves, remove the user and the seat line in the same change.
Seat prices, extra-seat prices and partner pricing live on the partner page and in your partner portal. They are deliberately not repeated here, and they should not appear on your customer invoice either.
How should you handle usage and carrier pass-through?
SessionPBX is a bring-your-own SIP trunk phone system. External calls use the trunk you connect, from any SIP-compliant carrier, registered by IP or by credentials, and that carrier bills for numbers and calls. SessionTalk does not supply phone numbers or handle number porting in this model. Setup of the trunk itself is in how to connect a SIP trunk to a hosted PBX, and what to look for in a carrier is in choosing a SIP trunk provider for a hosted PBX.
Internal team calls stay on the platform and are included, with no per-minute charge from SessionTalk. SessionTalk adds no per-minute or per-second markup on carrier calls, and it does not sell bundled minutes. That means the only usage cost in the stack is the one your carrier bills.
You then choose how the customer sees it:
- Pass-through: show carrier charges for numbers and outside calls as a separate line, so the customer sees seats and usage apart.
- Folded in: include calling in the seat line, so the customer sees one recurring charge for voice.
Either works. Which one you pick is a pricing decision, so settle it with your pricing model and keep the invoice consistent once you have chosen.
What should appear on your customer's voice invoice?
The customer invoice is yours. It names you as the supplier, lists what they use in words they recognise, and says how they pay you. It should not mirror SessionTalk's partner invoice. Keep the line items qualitative here and put your own amounts against them in your invoicing tool. The checklist further down lists what to include; the short version is seats, calling (included or passed through), numbers if you recover them, any branding line, and your support.
App logo branding is worth a word. It puts your logo and in-app product name on the softphones. It is included on Teams Business and is an optional add-on on Teams Phone. Teams Phone and Teams Business are SessionPBX plan names. SessionPBX is a standalone phone system and isn't related to Microsoft Teams. Only show branding as its own invoice line if you charge for it separately.
If voice sits inside a wider managed IT contract, keep the voice lines visible anyway. It makes changes easier when a customer adds people, and it helps when you add services later, as described in adding hosted PBX voice services as an MSP.
Does hosted or self-hosted change the billing?
Not on your side of the counter: either way, you still invoice the end customer. What changes is your upstream bill and your own costs.
Lean self-hosted multi-tenant on your own servers when you want many customer tenants in one place. Self-hosted is available to approved partners only, with annual licences, and server, hosting and network costs are yours. SessionTalk can also host it, in the UK (London), the US (New York) or Singapore, and each region has its own database. Hosted plans offer monthly or annual billing.
On hosted, you create one SessionPBX project per customer under your partner account and own it. On self-hosted, you run many tenants on your server, each kept separate. The trade-offs are covered in self-hosted PBX vs PBX hosting for VoIP resellers, and the tenancy model in multi-tenant PBX for MSPs.
When you bring a new customer live, line their invoice up with their project from day one. The steps after a signed order are in MSP customer onboarding for hosted PBX.
Do you need VoIP billing software to resell SessionPBX?
Not from SessionTalk. Search results for VoIP billing are mostly standalone billing platforms built for ITSPs and VoIP providers. SessionPBX is the phone system you resell, not a billing engine, and it does not replace your invoicing or accounting tools.
Invoice from the tools you already use to bill IT or telecom customers. Your SessionPBX projects tell you who has seats; your carrier account tells you what numbers and calls cost; your own system turns that into the customer invoice. If you are still comparing partner programmes on how they handle billing, how to choose a VoIP reseller program has the questions to ask. Partner billing is documented in the SessionPBX partner documentation.
Invoice checklist
- Your company as the supplier, and their company as the customer (they buy voice from you, not from SessionTalk)
- Seat or user count, matching the people using the softphones
- Whether calling is included in the seat line or shown as a separate carrier pass-through, in words they will recognise
- Numbers, if you recover those carrier charges
- App logo branding only if you charge for it as its own line (included on Teams Business; optional add-on on Teams Phone)
- Your support or managed-service line, if voice sits inside a wider IT contract
- How they pay you, and on what term (your terms, not SessionTalk's)
- Do not copy SessionTalk's partner invoice or partner prices onto the customer invoice
- If you are not yet a SessionPBX partner, apply at /partners before you promise a billed customer tenant
FAQ
Is SessionPBX a VoIP billing system?
No. SessionPBX is the phone system you resell to your customers. SessionTalk bills your partner organisation for each customer subscription, and you invoice your customer with the invoicing and accounting tools you already use. It does not replace a billing platform, and you do not need one from SessionTalk to start reselling voice.
Who invoices the end customer?
You do, at your own price and on your own terms. SessionTalk bills your partner organisation, not your customer. There are no commissions to chase and no payouts to wait for, so the customer relationship and the invoice stay with you. Apply on the SessionPBX partner page to get partner pricing and a partner workspace.
How is this different from setting your VoIP price?
The pricing guide is about choosing the number on the invoice and protecting what you keep. This guide is about the structure underneath it: the carrier, platform and customer invoices, and whether you bill per seat, show usage, or pass carrier charges through. Use the two together when you build your first voice price list.
Should I pass through carrier usage or bundle it into the seat price?
Either is fine. SessionTalk adds no per-minute markup on carrier calls and sells no bundled minutes, so your carrier is the only source of usage charges for numbers and external calls. Whether you show that as a separate pass-through line or fold it into the seat line is a pricing choice for you to make.
Does self-hosted change who bills the customer?
No. You still invoice the customer either way. On self-hosted, SessionTalk bills annual licences to your partner organisation, and server, hosting and network costs are yours. On hosted, plans are billed monthly or annually and SessionTalk runs the platform. Choose the hosting model for operational reasons; the customer invoice stays with you.
What do billed users install?
Each billed user installs SessionTalk softphones for Windows, macOS, iOS and Android, set up by QR code or desktop link, so nobody types SIP settings. Keep your seat count matched to the people who have scanned in, and remove users from the project when they leave so the invoice stays accurate.
Ready to resell SessionPBX and bill your own customers? Apply to the SessionPBX Partner Programme. Want to check what your customers get first? See SessionPBX features.
