Invoice software for service businesses: invoices that agree with the work
Invoice software creates and sends invoices, repeats them for clients billed monthly, records payments and shows what each client still owes. PLYNTUM, business management software for agencies and service companies, keeps invoices, payments, expenses and receivables on the same client and project as the work, from $55 a month. Recurring invoices and a client portal start on the Core plan.
Key facts
- What it is
- Invoicing in PLYNTUM, business management software for agencies and service companies: invoices, payments, expenses and receivables kept on the client and project they belong to.
- Who it is for
- Agencies, studios, consultancies and other service businesses that invoice clients for hours, deliverables or a monthly fee.
- Where it is in PLYNTUM
- Finance, on each client and project, next to the tasks and logged hours; the client portal is created from the client record.
- Which plan
- Invoices, payments, expenses and receivables are on every plan; recurring invoices, the client portal and project profitability start on Core.
- Price from
- $55 a month per workspace for up to 5 members (Launch), or $44 billed annually; Core is $150 a month for 10 members ($120 billed annually). 7-day Launch trial, no card, no free plan.
- Limits
- Invoice drafts use approved, billable time only (Core); no card payments, bank feeds or RS.ge integration; recurring invoices are not emailed automatically.
What is invoice software, and who needs it?
Invoice software is what a business uses to bill its clients: it creates an invoice with lines, dates and a total, sends it, records the payment and keeps a list of what is still unpaid. “Invoicing software”, “billing software” and “invoice app” usually describe the same job. For a service business, every line has to agree with work the client accepted: an hour logged, a deliverable handed over, an extra agreed in writing. When the invoice and the work live apart, someone copies one into the other by hand, and the gaps become unbilled work or disputed lines.
What invoice software does
- Create and send invoices. Client details, lines, issue and due dates and tax where it applies, sent to the person who pays.
- Repeat invoices. A monthly fee is billed the same way each month, so a recurring invoice saves rewriting it.
- Record payments. Partial ones too, so a half-paid invoice still shows what is open.
- Show receivables. What each client owes today and how overdue each invoice is.
- Keep expenses. Costs paid for a client, to pass on or at least to know about.
Who it is for
Agencies, studios, consultancies and other small service businesses that invoice clients for hours, deliverables or a monthly fee. If you bill mostly by the hour, time and billing software covers time and invoices together. This page is about the invoice and what happens after it is sent.
How invoicing works in PLYNTUM
In PLYNTUM an invoice sits on the client and project it bills, in the same workspace as that client’s tasks, logged hours and expenses. On Launch you write each invoice with free-form lines; from Core you can also draft one from approved time. Either way, the tasks and hours behind each line sit on the same project, so a line that does not match the work shows up before the client sees it.
On every plan
- Invoices. Written on the client, then emailed or shared by link.
- Payments. Recorded against the invoice when the money arrives through your bank or payment provider, partial payments included.
- Receivables. Which invoices are unpaid and for how long, per client; receivables ageing also shows on the leadership dashboard.
- Expenses. Payments, purchases and direct expenses recorded against the client or project.
- Monthly fees. A retainer fee on the client creates an expected payment each month, so receivables show what is due before the invoice exists.
- Import and export. CSV import for clients, employees and expenses; invoices and expenses export to CSV for your accountant.
From Core
- Recurring invoices. Set up once: lines, VAT, currency, a day of the month from 1 to 28 and a lead time. PLYNTUM creates the invoice record on schedule and notifies you in the app; you send it. See retainer management.
- Draft invoices from approved time. Pick a client, optionally one project, and a period: approved, billable hours from approved weeks are priced at the billable rates set in PLYNTUM, one line per project and rate. The draft opens in the invoice editor, you can change every line, and nothing is issued until you issue it. Hours already in a draft or an invoice are not billed twice.
- Client portal. A private, read-only link per client shows their invoices, payments and what is outstanding and overdue, but not your internal notes, time or costs. See the client portal.
- Project profitability. Logged hours at each person’s loaded hourly cost, plus direct expenses, set against the project value while the work runs. Every logged hour counts, and a manager approves each person’s week, which locks it.
- Cash flow overview. Expected receipts and planned payments for the next 13 weeks.
Currency and tax
The workspace has its own currency, and finance records can hold amounts in more than one currency. A PLYNTUM invoice is a request for payment, not a tax invoice: where VAT invoices must go through a government system, such as RS.ge in Georgia, your accountant issues them there. The finance page lists what the module does and what it leaves to accounting.
Invoice software vs accounting software vs a spreadsheet template
All three can produce an invoice; they differ in what they connect it to. A spreadsheet template connects it to nothing, so you track who owes what yourself. Accounting software connects it to the books: the ledger, the bank and the tax return. Invoice software built for service work connects it to the client and the work, and leaves the books to accounting. Two of them can work side by side; the question is which one holds the invoice you send.
| Spreadsheet template | Accounting software | Invoice software for service work (PLYNTUM) | |
|---|---|---|---|
| Main job | Produce one invoice document | Keep the books: ledger, bank and tax | Bill clients and track what they owe, next to the work |
| Recurring invoices | Copy last month’s file | Depends on the product | From Core: created on schedule, sent by you |
| Payments and what is owed | A list you keep yourself | Usually matched against the bank | Recorded per invoice; receivables per client |
| Link to hours, tasks and projects | None | Usually none | Same client and project as the tasks, hours and expenses; from Core, a draft invoice from approved time |
| Ledger, tax returns and payroll | No | Yes, its core job | No |
| Official tax invoices (RS.ge in Georgia) | No | Depends on the product and country | No |
| Cost | Free | Depends on the product | From $55 a month per workspace |
For a few invoices a month, the free invoice template is enough. It starts to fail when invoice numbers spread over several files, hours are copied across by hand and the only list of unpaid invoices is in someone’s head.
Worked example: one client, one month, one partial payment
The figures below are an example, not a benchmark, and all amounts are before tax. A studio bills one client a retainer of $2,400 a month. In October the client also asks for a landing page outside the retainer. The studio agrees a price in writing, 16 hours at $75 an hour, and adds the page to the client’s project as its own task with a 16-hour estimate.
The invoices
- Invoice 2026-031, issued 1 October: the October retainer, $2,400, due 15 October. On Core it comes from the recurring invoice; on Launch you write it yourself.
- Invoice 2026-036, issued 24 October: the landing page, 16 hours × $75 = $1,200, plus a stock-photo licence re-billed at cost, $90. Total $1,290, due 7 November.
Before sending the second invoice, the studio checks it against the task: the team logged 18 hours, 2 more than agreed. The agreement said 16, so the invoice says 16. The 2 extra hours, $150 at the agreed rate, stay off the invoice but stay in the project’s cost. Billing 18 would have added a line the client never agreed to.
The partial payment
On 14 October the client pays $1,800 against invoice 2026-031. It is recorded against that invoice, which now shows as partly paid.
What is still owed on 31 October
| Invoice | Due | Amount | Paid | Still owed | Status |
|---|---|---|---|---|---|
| 2026-031 | 15 October | $2,400 | $1,800 | $600 | 16 days overdue |
| 2026-036 | 7 November | $1,290 | $0 | $1,290 | Not yet due |
| Total | $3,690 | $1,800 | $1,890 |
The arithmetic: $2,400 − $1,800 = $600 still open on the first invoice; $600 + $1,290 = $1,890 owed in total, of which $600 is overdue and should be chased first. From Core, the client sees the same two invoices and the same $1,890 in the portal, so your reminder and the client’s own view agree.
What it costs for a 10-person team
PLYNTUM is priced per workspace with members included, not per user. A team of 10 needs Core, because Launch holds up to 5 members. Core costs $150 a month, or $120 a month billed annually: $1,440 a year, which works out at $12 per person a month for 10 people. Core includes everything on Launch plus recurring invoices, draft invoices from approved time, the client portal, project profitability, timesheet approval and the 13-week cash flow overview, for up to 25 active clients and 50 projects.
- Launch: $55 a month, or $44 billed annually; up to 5 members, 10 active clients and 20 projects. Invoices, payments, expenses and receivables, without recurring invoices or the client portal.
- Scale: $450 a month, or $360 billed annually; up to 25 members, with no client or project limit.
Annual billing is 20% off. Signing up starts a 7-day Launch trial with no card, and there is no free plan. If only two or three people handle the money and nobody else needs the workspace, Launch can be enough for invoicing alone. Plan details are on the pricing page, and the small business page works through what a 7-person studio pays.
What PLYNTUM does not do, and when other invoicing is enough
PLYNTUM’s invoicing is built around the client and the work, not around card payments or bookkeeping. It does not issue or send invoices for you, collect money or file anything with the tax office. If those are the jobs you need done, a dedicated invoicing tool or your accounting software may suit you better, and sometimes a template is all you need.
What PLYNTUM does not do
- Invoices from unapproved time. From Core, PLYNTUM drafts invoices only from approved, billable time: unapproved and non-billable time are left out, time without a rate is shown separately and not drafted, and time logged to a retainer instead of a project is not billed hourly. On Launch, invoices are written with free-form lines.
- Payment processing. PLYNTUM does not collect card payments. Money arrives through your bank or payment provider, and you record it against the invoice.
- Accounting and tax. No ledger, bank feeds, tax filing or payroll. Nothing is submitted to a government e-invoicing system, and no VAT invoices or waybills are issued in RS.ge.
- Automatic sending. Recurring invoices are created on schedule but not emailed, a draft from approved time is not issued or sent until you issue it, and payment reminders are not sent for you.
- Integrations and apps. QuickBooks, Xero and other integrations are planned, not available, and there is no native mobile app.
When a dedicated invoicing tool is the better fit
- You bill by the hour and want tracked time to become invoice lines without a weekly approval step. Some time trackers do this; the Harvest alternatives page compares several.
- You want clients to pay by card straight from the invoice.
When your accounting software or a template is enough
If you work alone or with one partner, send a few invoices a month and match them to the bank, the invoicing in your accounting software may be all you need. A fixed monthly fee with no extras needs no link to hours, and an occasional invoice needs only a template. PLYNTUM earns its place when several people deliver the work and each invoice has to agree with what they did.
Set up invoicing in one week
You do not need to move every client at once. Start with the clients you invoice this month and the invoices that are still open, so receivables are complete from the first day. Days 1 to 4 work on any plan, including the 7-day Launch trial with no card; day 5 needs Core, because recurring invoices and the client portal start there.
- Day 1: workspace and currency. Set the company name, time zone and currency, and add the clients you bill now, from a CSV file if you have a list.
- Day 2: open invoices. Re-create unpaid invoices by hand, with due dates and any part already paid, so receivables show what each client really owes.
- Day 3: projects and fees. Open the projects you will invoice and set the monthly fee on retainer clients.
- Day 4: expenses. Record this month’s direct expenses on their client or project and decide which you re-bill.
- Day 5: recurring invoices and the portal (Core). Set up a recurring invoice for each retainer and send each client their portal link.
- Month end. Before sending each invoice, compare its lines with the tasks and hours on the project. Record payments as they arrive and chase the oldest overdue invoice first.
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