Record a Supplier Purchase

Every time you pay a supplier — a service provider, a software subscription, office supplies, rent — you should record it in Prometheus. This allows the system to calculate your real costs and show you whether your business is profitable.

By the end of this guide: the expense is recorded, appears in your financial dashboard, and you have a permanent trace of the received invoice.

When to Use This Guide

  • You have received a supplier invoice and need to log it
  • You have just paid for a service (subscription, contractor, equipment)
  • You want to track all your expenses to know your actual profit

Step 1 — Open the Purchase Module

  1. In the left menu, click Business Suite
  2. In the submenu, click Purchase Invoices (or Purchases)
  3. The list of your recorded purchases appears

Step 2 — Create a New Purchase Record

  1. Click New Purchase in the top-right corner
  2. The purchase form opens

Step 3 — Select the Supplier

  1. Click in the Supplier field
  2. Start typing the supplier’s name — if they are in your contacts, they will appear in the dropdown
  3. Select them. If they do not exist yet, click Create New Supplier and enter their name and contact details

Step 4 — Enter the Date and Reference Number

  1. Invoice Date: the date printed on the supplier invoice you received (not necessarily today)
  2. Supplier Invoice Number: the reference number printed on the invoice — this helps you locate this document again later very quickly

Step 5 — Add Expense Lines

  1. Click Add a Line
  2. In Description, type what you purchased (e.g. “Accounting software subscription — March 2026”)
  3. In Quantity, type 1 (or the actual quantity if you are buying multiple units)
  4. In Unit Price (excl. VAT), type the pre-tax amount
  5. Select the VAT rate mentioned on the supplier invoice
  6. Prometheus calculates the total including VAT automatically

Step 6 — Attach the Received Invoice (Optional but Recommended)

Attaching the invoice file gives you full traceability and protects you in the event of an audit:

  1. Click Attach File
  2. Select the PDF or photo of the invoice from your computer
  3. The file is attached to this record

You can retrieve this invoice at any time by clicking the purchase entry in the list.

Step 7 — Save

  1. Review all amounts carefully
  2. Click Save

The expense immediately appears in your list and in your financial dashboard.

Frequently Asked Questions

I do not have the invoice right now. Can I record the expense anyway? Yes. You can record the purchase without an attachment and add the file later by reopening the record and clicking Edit.

How do I record a recurring monthly subscription? Create a purchase record as described above. Prometheus will soon allow you to mark an expense as recurring so you do not have to re-enter it each month.

My expense is in a foreign currency (USD, GBP…). How do I enter it? Enter the amount converted to your local currency at the exchange rate applicable on the payment date. Note the exchange rate used in the Description field for your own reference.