<div class="gn-article"><div class="gn-hero gn-reveal"> <div class="gn-hero__image"><img src="https://cdn.prod.website-files.com/687a235da6861294eec73166/6a0e1156d2882114cec98e9d_the-numbers-nobody-talks-about-banner-6a06f32e3284f680551237.jpeg" alt=""></div> <div class="gn-hero__head"> <span class="gn-kicker"><span class="dot"></span>Growth</span> <h1 class="gn-title">The Numbers Nobody Talks About: Lock-Up Days</h1> <div class="gn-meta"> <strong>The GO Network</strong> <span class="pip"></span> <span>15 May 2026</span> <span class="pip"></span> <span>3 min read</span> </div> </div> </div> <div class="gn-body"> <p class="gn-lede gn-reveal">Lock-up days is the total number of days of revenue tied up in your business at any given point, expressed as a single number. It is calculated by adding your debtor days (how long clients take to pay invoices) to your work-in-progress days (how long it takes you to bill for work once it's done).</p> <p class="gn-reveal">The formula is straightforward: divide your total lock-up (WIP plus debtors) by your average daily revenue. The result tells you, in plain terms, how many days of income you are currently financing on behalf of your clients.</p> <div class="gn-divider gn-reveal" aria-hidden="true"></div> <h2 class="gn-reveal">What good looks like</h2> <p class="gn-reveal">Typical lock-up for agencies sits somewhere between 45 and 90 days, though the range is wide and varies considerably by agency type, size, and client mix. Smaller agencies under £3m AGI often run higher lock-up, sometimes above 90 days, because they lack the billing discipline and contractual leverage that larger shops have built up over time.</p> <p class="gn-reveal">Project-based agencies tend to carry more WIP risk than retainer-heavy businesses. If most of your revenue is on rolling monthly retainers with predictable billing cycles, your lock-up should be towards the lower end. If you work on long projects with milestone billing, you can drift well above 75 days without anyone noticing until it bites.</p> <p class="gn-reveal">Agencies with strong new-business momentum and fast headcount growth are especially exposed. Revenue is rising, but billing and collection haven't kept pace. Lock-up days can balloon quickly in a growth phase, even when the P&L looks healthy.</p> <div class="gn-stats gn-reveal"> <div class="gn-stat"><span class="gn-stat__num">45–90</span><span class="gn-stat__label">Typical lock-up days range for agencies.</span></div> <div class="gn-stat"><span class="gn-stat__num">90<em>+</em></span><span class="gn-stat__label">Days lock-up for smaller agencies under £3m AGI.</span></div> <div class="gn-stat"><span class="gn-stat__num">£200<em>k</em></span><span class="gn-stat__label">Cash released on a £5m AGI business reducing lock-up by 15 days.</span></div> </div> <div class="gn-divider gn-reveal" aria-hidden="true"></div> <h2 class="gn-reveal">Where it goes wrong</h2> <p class="gn-reveal">The most common failure mode is slow invoicing. Work gets done, the client is happy, and the account team moves on to the next brief. Raising the invoice becomes an afterthought. Every day between delivery and billing is a day you are funding the client's business, not yours.</p> <p class="gn-reveal">The second failure mode is weak payment terms, or terms that exist on paper but aren't enforced. Thirty-day terms that routinely become sixty or ninety days are not thirty-day terms. If your finance team is reluctant to chase, or if account directors feel awkward about payment conversations, the problem compounds month on month.</p> <p class="gn-reveal">A third, less obvious problem is scope creep that never gets billed. Work expands, the team absorbs it, and nobody raises a change order. That work sits in WIP indefinitely, or gets written off entirely. Both outcomes inflate your lock-up and erode your margin at the same time.</p> <aside class="gn-quote gn-reveal"><q>Your agency is effectively extending six-figure credit lines to clients without any of the commercial terms a lender would demand.</q></aside> <p class="gn-reveal">In aggregate, these failure modes can mean your agency is effectively extending six-figure credit lines to clients without any of the commercial terms a lender would demand. That is a significant drag on cash flow, and it is entirely within your control to fix.</p> <div class="gn-divider gn-reveal" aria-hidden="true"></div> <h2 class="gn-reveal">What to do about it</h2> <p class="gn-reveal">Start by measuring it. Pull your WIP balance and your aged debtors report, add them together, and divide by your average daily revenue. If you don't know the answer within five minutes, that itself is a finding.</p> <p class="gn-reveal">Set a lock-up target and review it monthly alongside your other trading metrics. For most agencies, a realistic improvement goal is reducing lock-up by 10 to 15 days over two to three quarters. That may sound modest, but on a £5m AGI business it can release £150,000 to £200,000 in cash.</p> <p class="gn-reveal">Tighten your billing triggers. Every project should have a defined point at which an invoice is raised, agreed in the contract before work starts. Retainers should be billed in advance, not in arrears. And finance should have a clear mandate to chase overdue invoices without needing account team sign-off to do so.</p> <aside class="gn-callout gn-reveal"> <div class="gn-callout__label">What this means for you</div> <h4>Three failure modes to fix now.</h4> <ul> <li><strong>Slow invoicing.</strong> Every day between delivery and billing is a day you are funding the client's business, not yours.</li> <li><strong>Weak payment terms.</strong> Thirty-day terms that routinely become sixty or ninety days are not thirty-day terms. If account directors feel awkward about payment conversations, the problem compounds month on month.</li> <li><strong>Unbilled scope creep.</strong> Work expands, the team absorbs it, and nobody raises a change order. That work sits in WIP indefinitely, or gets written off entirely.</li> </ul> </aside> <div class="gn-divider gn-reveal" aria-hidden="true"></div> <h2 class="gn-reveal">The Question Worth Asking</h2> <p class="gn-reveal">If your agency stopped winning new work tomorrow, how many days could you operate on the cash currently locked up in WIP and outstanding invoices, and does that number feel acceptable to you?</p> </div></div>