Accounts Receivable Management: DSO, Ageing Analysis and Credit Policy

The Silent Cash Flow Killer

A business can be profitable on paper and insolvent in practice. The mechanism that makes this possible is slow-paying or non-paying customers. Revenue is recognised when performance obligations are met under IFRS 15, but cash arrives only when the customer actually pays. The gap between those two events is the accounts receivable balance, and how that balance is managed determines whether a growing, profitable business is also a cash-generative one.

For B2B businesses with net payment terms — where customers are invoiced after delivery and given 30, 60, or 90 days to pay — the accounts receivable balance can represent a material proportion of monthly revenue. A business with £500,000 of monthly revenue and 60-day average payment terms has approximately £1m tied up in receivables at any given time. Reducing average payment terms from 60 to 45 days releases £250,000 of cash — cash that is already in the P&L as profit but has not yet arrived in the bank.

Growing businesses frequently deprioritise receivables management because the collections conversation feels awkward, because the finance team is stretched, or because there is no documented credit policy to enforce. The result is a slow creep in DSO that is not noticed until a cash flow crisis makes it visible. The cure at that stage is painful: the business either needs to draw down debt, delay its own payments, or confront multiple large customer debts simultaneously. Prevention is straightforward; it just requires discipline.

How to Calculate DSO Correctly

Days Sales Outstanding measures how long, on average, it takes the business to collect cash after a sale. The formula is: DSO = (trade receivables / revenue) multiplied by the number of days in the period. For a monthly snapshot, the denominator is typically the revenue in the most recent month multiplied by the number of days in that month, or the annualised revenue divided by 365.

The most common calculation errors are: using annual revenue in the denominator for a monthly receivables balance (which understates DSO if the business is growing, because revenue has grown but receivables reflect a shorter period); including non-trade receivables (VAT receivables, prepayments, intercompany balances) in the numerator (which overstates DSO); and using gross receivables before the bad debt provision rather than net receivables (which slightly overstates DSO).

DSO benchmarks vary significantly by business model. B2B software businesses with 30-day payment terms should target a DSO of 30 to 45 days. Professional services firms with 30-day terms often run 45 to 60 days due to dispute resolution and approval cycles. Enterprise contract businesses with 60 or 90-day payment terms should target DSO at or close to their stated terms, so 60 to 90 days. E-commerce businesses that require payment at checkout have a negative DSO (cash arrives before or at delivery, creating deferred revenue rather than receivables).

The Debtor Ageing Analysis

The debtor ageing analysis is the most important day-to-day tool in AR management. It segments the total receivables balance into buckets by how long each invoice has been outstanding, and the pattern of overdue balances tells the finance team where to focus collection effort.

The ageing analysis should be reviewed weekly by the finance team and monthly by the CFO or Finance Director. The key metrics to track are: the percentage of total receivables in each bucket; the total value of invoices 90+ days overdue as a percentage of revenue (a credit quality indicator); and the change in each bucket from the prior month. A growing 61-90 day bucket is an early warning signal of a deteriorating collections position that requires immediate attention.

Setting a Credit Policy

A credit policy is the set of documented rules that govern who the business extends credit to, on what terms, and to what amount. It is the primary tool for preventing bad debts before they occur. The credit policy should cover: credit terms offered by customer type (enterprise customers may receive 60 days; SME customers may be required on 30 days; any new customer should be on 30 days until payment history is established); credit limits by customer (the maximum outstanding balance permitted for each customer); the credit assessment process for new enterprise customers; and the circumstances in which upfront payment or advance payment is required.

Credit limits should be set based on a customer's financial capacity to pay. For large enterprise customers, this means reviewing public accounts or credit reference agency data. For SME customers, a simple credit check from Dun & Bradstreet or Experian Business is sufficient. A business that extends unlimited credit to any customer who asks is not operating a credit policy; it is operating an implicit policy of unlimited credit risk, which will eventually produce a material bad debt.

The decision matrix for payment terms versus upfront payment should be explicit. Indicators that suggest requiring upfront payment include: new customer with no payment history; customer in a sector with elevated insolvency risk; customer that has previously paid slowly; transaction amount materially above the customer's normal order size; or customer that operates in a jurisdiction where enforcement of invoices is difficult.

The Collections Process

An effective collections process operates through a defined sequence of escalating actions, triggered automatically by the invoice due date rather than requiring manual intervention at each stage. The standard automated sequence is: three-day pre-due reminder (courteous email reminding the customer their invoice is due shortly); day one overdue (automated reminder email); day seven overdue (second automated reminder, slightly more direct in tone); day fourteen overdue (third automated reminder, now including a statement of account); day thirty overdue (escalation to account manager for direct contact; this is the point at which an automated process must transition to a human one).

At thirty days overdue, the account manager or customer success manager should make direct contact with the customer to understand why the invoice has not been paid. In the majority of cases at this stage, the reason is administrative: an invoice approval bottleneck, a purchase order that was never raised, or an accounts payable processing backlog. These issues can typically be resolved quickly once identified. The minority of cases at 30 days that are not administrative are the ones that require careful management.

At sixty days overdue, a formal letter before action should be issued, stating the intention to pursue the debt through legal channels if not paid within a specified period (typically 7 to 14 days). At ninety days overdue, the business should refer the debt to a commercial debt collection agency or instruct solicitors to issue a claim under the Pre-Action Protocol for Debt Claims. Service should typically be suspended to prevent further debt accumulation.

Invoice Factoring and Discounting

Invoice finance allows a business to convert outstanding receivables into immediate cash by selling them to a finance provider at a discount. It is a legitimate working capital tool for businesses with strong sales but slow payment cycles, and for businesses that are growing faster than their operating cash flow can support.

Invoice discounting is a confidential facility: the business retains responsibility for collections, and the customer does not know that the invoice has been financed. The finance provider advances 70 to 90% of the invoice value on issuance and pays the balance (less fees) when the customer settles. Invoice factoring is a full-service facility where the finance provider takes over collections and the customer makes payment directly to the provider. Factoring is more expensive but removes the collections workload from the business.

The cost of invoice finance is typically expressed as a service fee (0.2 to 1.0% of turnover) plus a discount charge (interest on the drawn balance, typically base rate plus 2 to 4%). The all-in cost ranges from approximately 5 to 10% per annum on the financed balance. This cost should be compared against the cost of the working capital problem it solves: if the alternative is a bank overdraft, the cost comparison is straightforward.

Bad Debt Provision Under IFRS 9

IFRS 9 requires the use of an expected credit loss model for trade receivables. For trade receivables that do not have a significant financing component (i.e., standard commercial credit terms rather than long-term financing arrangements), the simplified approach is permitted and widely used. Under the simplified approach, lifetime expected credit losses are recognised from day one for all trade receivables, regardless of whether credit risk has increased since initial recognition.

The most common implementation of the simplified approach is a provision matrix: a table that applies expected loss rates to each ageing bucket. A typical provision matrix might apply: 0.5% to current invoices; 2% to invoices 1 to 30 days overdue; 5% to invoices 31 to 60 days overdue; 15% to invoices 61 to 90 days overdue; and 50 to 100% to invoices 90+ days overdue.

The expected loss rates should be calibrated against the business's own historical default experience. A business that has never written off a debt can justify lower rates; a business that has experienced material write-offs in prior years should reflect that experience in its rates. The provision matrix should be reviewed at least annually and updated whenever there is a material change in the credit environment (a sector-wide downturn affecting the customer base, a concentration of receivables in a distressed customer).

Key Takeaways

• DSO is calculated as trade receivables divided by daily revenue. Use the most recent period's revenue, not annual revenue, for an accurate monthly calculation. DSO benchmarks are 30 to 45 days for B2B SaaS, 45 to 60 days for professional services, and 60 to 90 days for enterprise contracts.
• The debtor ageing analysis segments receivables by overdue period and drives the collections action for each bucket. Review it weekly at the operations level and monthly at the CFO level.
• A credit policy must document: credit terms by customer type, credit limits, the assessment process for new customers, and the circumstances in which upfront payment is required. An undocumented policy is not a policy.
• The collections process should be automated up to 30 days overdue and human-driven from 30 days. The account manager must make direct contact at 30 days; a formal letter before action goes out at 60 days; legal referral at 90 days.
• Invoice discounting and factoring are working capital tools, not distress signals. The best time to establish a facility is before it is needed, when DSO is healthy and the receivables book is clean.
• IFRS 9 requires a provision matrix under the simplified approach for trade receivables: expected loss rates applied to each ageing bucket, calibrated to historical default experience, reviewed annually.
• The single highest-impact action for most growing B2B businesses with AR challenges: build an automated reminder sequence. Businesses that send polite, consistent reminders from day one collect faster than those that rely on customers initiating payment unprompted.