The Real Cost of a Slow AR Cycle (and How to Calculate It)

If you run a business that invoices clients, you've dealt with slow AR. A client takes 45 days to pay instead of 30. Another one is 60 days out and still hasn't responded to your follow-ups. It's frustrating, but most owners chalk it up as just how business works.

It's not. Slow collections have a real dollar cost, and most of the time, owners have no idea what that number actually is.

Here's how to figure it out, and what to do about it.

Start with your DSO

Days Sales Outstanding (DSO) is the average number of days it takes you to collect payment after an invoice goes out. It's the single most useful number for understanding how healthy your AR cycle is.

The formula is simple:

DSO = (Accounts Receivable / Total Credit Sales) x Number of Days

So if you have $150,000 in open receivables, you did $500,000 in credit sales over the last 90 days, your DSO is 27 days. If your payment terms are Net 30, that's actually good. If you're seeing a DSO of 50 or 60, you have a problem.

The average DSO across small businesses in professional services, construction, and staffing runs between 45 and 65 days. Most of those businesses have Net 30 terms. That gap, 15 to 35 days of extra float sitting with your clients instead of in your account, is where the cost lives.

What that float actually costs you

There are three places slow AR hits your bottom line. Most owners only think about the first one.

The first is borrowing cost. If your cash is tied up in unpaid invoices, you're either drawing on a line of credit to cover operating expenses or you're sitting on less cash than you should be. Either way, there's a cost. If you're borrowing at 8% annually and you have $200,000 sitting in overdue AR, that's roughly $13,000 a year in interest, just to float your own customers.

The second is the cost of chasing. Someone on your team is sending reminder emails, making calls, and following up on invoices that should have already been paid. Even if it's just a few hours a week, that time adds up. At $50/hour, 3 hours a week is $7,800 a year. Most businesses spend more than that.

The third is bad debt. The longer an invoice goes unpaid, the less likely it is to get paid at all. Invoices unpaid at 90 days have roughly a 26% chance of becoming uncollectible. At 120 days, that number climbs toward 57%. If you're not actively managing collections, you're quietly writing off revenue you already earned.

Run the math on your business

Here's a quick way to put a number on it:

1.  Pull your current DSO

2.  Subtract your payment terms (e.g., 30 days)

3.  Multiply that gap by your average daily revenue

4.  That's the cash sitting in your AR that shouldn't be

Say your DSO is 52 days on Net 30 terms. That's a 22-day gap. If your business does $2M a year, your daily revenue is about $5,500. Multiply that by 22 and you've got roughly $121,000 in cash that's yours but not in your account. At a modest borrowing rate of 8%, that's nearly $10,000 a year in direct cost, before you count collections time or bad debt.

For most SMBs, the total cost of a slow AR cycle runs between 3% and 6% of annual revenue. On a $2M business, that's $60,000 to $120,000.

The fix isn't chasing harder. It's automating the process

The reason most businesses have slow AR isn't that their clients are bad. It's that no one is consistently following up. An invoice goes out, a reminder gets sent when someone remembers, and then it sits.

Consistent, automated outreach changes the dynamic. When clients know they'll get a reminder at day 5, another at day 15, and a more direct message at day 30, they pay faster. It's not about being aggressive. It's about being reliable. Clients who know you're paying attention tend to pay on time.

The businesses that get DSO under 30 days aren't doing anything magic. They have a process that runs every time, without anyone having to remember to do it.

Bottom line

Slow AR is not just an inconvenience. It's a cash flow tax you're paying on revenue you already earned. Most businesses don't calculate it because it feels intangible, but it's real, it compounds, and it's fixable.

If you want to see what your AR cycle is actually costing you, start with your DSO. The number might surprise you.

Arclite is a cash flow management platform built for small and mid-sized businesses. It integrates directly with QuickBooks Online to automate AR collections, AP processing, and cash forecasting.