In businesses of all sizes, understanding the essential elements of financial business documents is important. Two of the most critical documents are invoices and purchase orders. These documents serve distinct purposes and are integral components of an efficient business operation, whether managed in-house or by virtual bookkeeping services.

In this article:

Definitions and purpose

1. Invoices

An invoice is a document issued by a seller to a buyer, requesting payment for goods or services provided. It is generated after the goods or services have been delivered. An invoice generally includes:

  • Invoice number
  • Date of issuance
  • Seller information
  • Buyer’s company information
  • Itemised list of goods or services, quantities, and prices
  • Total amount due
  • Payment terms
  • Due date

The primary purpose of an invoice is to request payment from the buyer. It serves as a detailed record of the transaction and provides the necessary information for the buyer to make the payment. Invoices are crucial for maintaining financial records, managing cash flow, and ensuring timely payments.

2. Purchase orders

A purchase order (PO) is a document created by a buyer to request goods or services from a supplier. It is a formal offer issued by the buyer, detailing the types, quantities, and agreed prices for products or services. A purchase order typically includes:

  • Purchase order number
  • Date of issuance
  • Supplier information
  • Buyer’s company information
  • Item descriptions, quantities, and prices
  • Delivery dates and locations
  • Payment terms

The primary purpose of a purchase order is to establish clear communication between the buyer and the seller. It serves as a legal document that binds the seller to deliver the specified goods or services at the agreed-upon terms once accepted. Purchase orders help businesses manage orders systematically, control spending, and prevent unauthorised purchases.

Key differences between invoices and purchase orders

Despite their similarities in facilitating business transactions, purchase orders and invoices have several key differences:

Initiation and Timing

The purchase order is initiated by the buyer before the transaction occurs. It is a proactive document that outlines the buyer’s intent to purchase goods or services. The invoice is issued by the seller after the transaction has taken place. It is a reactive document that requests payment for goods or services already delivered.

It’s worth noting at this stage that businesses may have different contract terms – so the terms outlined by a supplier in a quote may not be accepted by the buyer. The buyer may, in fact, accept the quote under their own standard contract terms, which might not suit the seller. This is sometimes called the ‘battle of the forms’ and both parties will need to communicate clearly so that they are happy with the terms before a contract is signed or approved.


A purchase order is used to request goods or services and to provide formal documentation of what is being ordered. It acts as a contract once accepted by the seller. The invoice requests payment for goods or services that have been delivered. It acts as a bill that the buyer must pay.


The purchase order focuses on the details of the order, such as quantities, prices, and delivery dates, whereas an invoice focuses on the details of the payment, including the total amount due, payment terms, and due date.

Financial Impact

The purchase order does not directly affect the financial accounts of the buyer or seller until the order is fulfilled, but an invoice directly impacts the financial accounts, as it records the amount owed by the buyer and the amount receivable by the seller.

Usage in bookkeeping

In bookkeeping terms, a purchase order helps with budgeting and financial planning, as it provides an estimate of future expenditures. An invoice, which is used both for accounts payable by the buyer and accounts receivable for the seller, directly influences cash flow and financial statements.

Invoices and purchase orders in practice

To better understand the distinctions between purchase orders and invoices and how virtual bookkeeping services facilitate their management, let’s explore a few practical scenarios:

Scenario 1: A retail business ordering stock

A retail business needs to restock its office supplies. The procurement manager creates a purchase order, specifying the quantities, prices, and delivery date. The supplier receives the purchase order, reviews it, and confirms acceptance. Once the goods are delivered, the supplier generates an invoice and sends it to the retail business. For either business, a virtual bookkeeping service can match the invoice with the purchase order, verifying that the goods sent or received align with the order. Ideally, the retailer then schedules the payment according to the agreed terms, ensuring timely settlement and accurate record-keeping.

Scenario 2: A service-based company billing a client

A consulting firm completes a project for a client. The firm uses a virtual bookkeeping service, and the virtual assistant creates an invoice detailing the services provided, hours worked, and total amount due. The invoice is automatically sent to the client either through an accounting software platform or direct. The client reviews the invoice and processes the payment. The virtual bookkeeping system updates the firm’s accounts receivable. If the payment is not received by the due date, the virtual assistant sends reminders to the client, helping the consulting firm maintain steady cash flow.

Scenario 3: Budgeting and financial planning

A business wants to look at planning for the next six months. It uses historical financial data, which is up to date and accurate because it uses an experienced virtual bookkeeping service. By reviewing past invoices, the business can assess payment trends and plan for expected cash inflows. This data-driven approach enhances financial planning and ensures that the company is prepared for future financial commitments.

Are bookkeeping services necessary for small businesses?

Despite their size, micro and small businesses must still deal with financial transactions that are integral to their daily operations, ranging from sales and purchases to payments and receipts. For your business to succeed, good bookkeeping isn’t just recommended – it is critical element of a successful business strategy.

Bookkeeping helps your business to grow

Good bookkeeping is key to small business growth. It allows you to keep your finger on the pulse of your financial health, providing insights into cash flow trends, profitability patterns, and revenue sources. With this valuable data at your disposal, you can create strategic plans that drive expansion and scalability.

Efficient bookkeeping also helps to identify areas of the business that yield the most profit and those that may not be as lucrative. While your virtual assistant may not do this analysis for you, they will make sure that your financial records are up to date, so that you have access to the latest accurate information. Armed with this knowledge, you can revise your existing approach to make the most of the opportunities available to you.

Ensuring financial stability

Financial stability is fundamental to the long-term success of any enterprise. Diligent bookkeeping paves the way for small businesses to maintain a steady financial course. By keeping accurate records of all financial transactions, you can be confident that you are managing your day-to-day expenses effectively, avoiding the pitfalls of overspending or under-budgeting.

Good bookkeeping also allows you to demonstrate your financial controls and competence, which is essential for applying for business loans or other funding.

Meeting legal and regulatory requirements

Small businesses must adhere to certain tax laws and financial regulations. For the purposes of outsourcing your bookkeeping, you particularly need to be aware of the UK’s Money Laundering Regulations. If you manage your books yourself, you don’t need to worry about this – your accountant will handle that, However, if you’re thinking about outsourcing to a bookkeeper, you need to be sure that they both understand and comply with this legislation.

The role of virtual bookkeeping services

Virtual bookkeeping services have revolutionised how start-up. micro and small businesses manage their daily financial transactions. These services help to ensure accuracy, compliance with financial regulations, timely processing of transactions, and can offer valuable insights into financial management through the proper handling of invoices and purchase orders.

Virtual bookkeeping services provide small businesses with cost-effective, scalable bookkeeping solutions tailored to their unique needs, freeing up time for business owners to focus on growth. While it is possible for a small business to manage without professional bookkeeping services, you may increase the risk of errors, potentially leading to financial instability. If you have no financial background, it can also take up many hours of time, and cause unnecessary stress.

Effectively managed small business bookkeeping solutions can provide critical insights into business performance, profitability analysis, cash flow trends, and predictive financial forecasting, aiding in informed decision-making. An outsourced bookkeeping service can also work with whatever financial software you are using, ensuring that records are accurate and up to date at all times.

These services offer several advantages:

Efficiency and accuracy

Virtual bookkeeping services can be used to create, track and manage purchase orders, invoices, payments and general accounting. This ensures that your records are accurate and consistent and that your business’s financial management is reliable.

Improved cash flow management

Effective purchase order and invoice management is crucial for maintaining healthy cash flow – something that is vital for all small businesses. Virtual bookkeeping services monitor due dates, send reminders for overdue payments, and forecast cash flow based on outstanding invoices and purchase orders. This proactive approach helps businesses avoid cash flow crunches and ensures they have enough liquidity to meet their obligations.

Enhanced record-keeping and reporting

Virtual bookkeeping services offer robust record-keeping capabilities, storing all purchase orders and invoices in a centralised, secure, and easily accessible format that’s agreed with you. This simplifies audit trails, compliance reporting, and financial analysis. Your virtual assistant may also be able to generate reports to understand purchasing patterns, supplier performance, and customer payment behaviours, giving you valuable insights into the financial performance of your business.

Integration with other systems

Virtual bookkeeping services don’t have to stand on their own. Depending on the other systems you have in your business, such as Xero book keeping financial software, for example, your virtual assistant can integrate finance elements with other business systems such as CRM software. This integration ensures that purchase orders and invoices are aligned with customer interactions, providing an all-round view of the business operations and helping you to improve your customer service.
The importance of bookkeeping services extends far beyond mere record-keeping. For small businesses, investing in efficient bookkeeping is tantamount to investing in growth, stability, and future success. It is the bedrock upon which a sustainable business model is built and an indispensable tool for navigating the challenging landscape that is small business ownership.

Whether it’s through hiring a professional bookkeeper, using software solutions, or a combination of both, embracing effective bookkeeping practices is a wise decision for any small business aiming to thrive in today’s competitive market.

The benefits of using virtual bookkeeping services

Choosing to use virtual bookkeeping services to manage purchase orders, invoices and other business expenses offers particular benefits to micro and small businesses. These include:

Cost Savings

By outsourcing these financial tasks, you save considerable time and cost that you would otherwise spend on trying to keep on top of your books yourself. This not only results in savings – it also frees up your time to concentrate on revenue-generating activities such as strategy and sales.

Accessibility and convenience

Virtual bookkeeping services are accessible from anywhere with an internet connection, offering flexibility and convenience. Particularly when using accounting software, business owners can review financial documents, approve purchase orders, and monitor invoices remotely, making it easier to manage finances on the go. A virtual service is more flexible than an in-house employee, because you reduce your overheads, and your assistant is always available when you need them.

Enhanced security

The best virtual bookkeeping services employ robust security measures to protect sensitive financial data. Encryption, secure cloud storage, and regular backups ensure that purchase orders, invoices, and other financial documents are safe from unauthorised access and data loss. So even though you have outsourced your day-to-day financial management, you can be confident that your data is secure.


You want your business to grow, and virtual bookkeeping services can easily scale with you. Whether you are expanding its operations, adding new products, or entering new markets, the bookkeeping service can adjust to meet increasing demands, ensuring continued efficiency and accuracy.

Managing purchase orders and invoices successfully

While purchase orders and invoices are both essential documents in business transactions, they serve distinct purposes and are used at different stages of the procurement process. Purchase orders are initiated by buyers to request goods or services, providing a framework for the transaction, while invoices are issued by sellers to request payment for delivered goods or services.

Understanding these differences is crucial for effective financial management. Virtual bookkeeping services play a pivotal role in managing purchase orders and invoices, and by using these services, small business owners can streamline financial processes, reduce costs, and gain valuable insights into their operations. The integration of virtual bookkeeping services not only simplifies the management of purchase orders and invoices but also contributes to the overall financial health and success of your business.

So if you would like to explore virtual bookkeeping services for invoices and purchase orders, feel free to call us on 0800 994 9016 or use our contact form in the menu above.


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