“How much should we be spending on marketing?” is one of the most common questions we hear at HUDL — and one of the most consistently mishandled. Some business owners set budgets based on what’s left over after other costs. Others pick a round number that feels manageable. A few copy what they assume competitors are spending.
None of these approaches gets you to the right number. This guide covers the frameworks that do, and the mistakes that quietly bleed SME marketing budgets every year.
Why Most SME Marketing Budgets Are Wrong
There are two failure modes, and they’re equally damaging.
The first is underspending. A business that allocates £500 a month to Google Ads, spreads it across ten campaigns, and wonders why nothing converts is not experiencing a Google Ads problem — it’s experiencing a budget problem. Most channels have a minimum viable spend below which they simply don’t have enough data or volume to work.
The second is misdistribution. A business spending £4,000 a month on marketing but splitting it roughly equally across paid search, social media, content, and SEO is almost certainly getting weaker results than a business putting £3,500 into the one or two channels that genuinely suit its market. Concentration beats dilution, nearly every time.
Getting the budget right isn’t just about the total number — it’s about allocation logic.
Framework One: Percentage of Revenue
The most widely cited approach is to set marketing spend as a percentage of revenue. For B2C businesses in competitive markets, the commonly used range is 7–12% of annual revenue. For B2B, where sales cycles are longer and customer lifetime values tend to be higher, the range is typically 5–8%.
These are guidelines, not rules. An early-stage business trying to build market share should weight towards the top of — or above — these ranges. A business in a stable niche with strong repeat custom and word-of-mouth can sit below them.
The percentage-of-revenue model is simple and self-scaling, which makes it practical for SMEs. Its weakness is that it’s backwards-looking: it sizes the budget relative to what you’ve already earned rather than what you’re trying to achieve.
Framework Two: Goal-Based Budgeting
A more commercially rigorous approach is to start with your growth target and work backwards.
Say you want to generate 20 new clients next quarter. Your average conversion rate from enquiry to client is 25%, which means you need 80 enquiries. Your current cost per enquiry across your best-performing channels is (illustratively) around £60–£80. That gives you a lead-generation budget in the range of £4,800–£6,400 for the quarter — before any brand, content, or overhead costs.
This method forces clarity. It makes your marketing budget a commercial decision, not a finance one. It also means you can defend the number with logic: “We need this much to achieve this outcome” is a stronger argument than “We spent this much last year.”
The practical challenge is that it requires reliable data on conversion rates and cost per lead. If you don’t have that yet, building measurement infrastructure is the first priority — which is itself worth budgeting for.
Framework Three: Zero-Based Budgeting
Zero-based budgeting starts from scratch each cycle. Every channel, tool, and activity must justify its inclusion rather than simply rolling forward from the previous year. This is the most demanding approach but also the most honest: it forces you to ask whether each line item is still earning its place.
For most SMEs this is worth doing annually, even if you use percentage-of-revenue or goal-based budgeting month-to-month. The discipline of a zero-based review prevents budgets from accumulating legacy spend — tools nobody uses, campaigns that haven’t been reviewed in six months, retainers that predate the current strategy.
How to Split the Budget Across Channels
Once you have a total figure, the question is how to divide it. There’s no universal formula, but there are sensible principles.
Prioritise channels with measurable returns first. Paid search (Google Ads) and paid social offer the clearest feedback loops — you can see what a click costs and what proportion convert. This makes them the right starting point for most SMEs, because you’ll learn quickly and can adjust.
Organic channels (SEO, content) require longer time horizons but compound over time. Budget for them as a proportion of total spend — illustratively, 20–30% — not as an afterthought once paid channels are funded. Our guide to Google Ads for small businesses covers how to think about the paid side of this split in more detail.
Reserve a small allocation — 10–15% — for testing. The channel that works best for your business at scale is almost never the channel you’d have predicted at the start. Testing budget funds the experiments that find the actual winners.
Common Mistakes That Waste SME Budgets
Not funding channels to a viable threshold. Spending £300 a month on Google Ads in a competitive market is not a test — it’s noise. Either fund a channel properly or don’t fund it at all.
Separating marketing budget from sales costs. If your marketing generates leads that are then handed to a sales team, the full cost of converting those leads should inform your budget decisions. Marketing and sales are one funnel.
Reviewing spend monthly but not performance. Budget reviews that only look at what was spent, not what it returned, are housekeeping rather than management. Attach spend review to outcome review.
Cutting marketing in a downturn. Marketing budget is typically one of the first costs cut when business slows. In most cases this compounds the problem. Maintaining spend through a slowdown — even at reduced levels — preserves position. Cutting it entirely often means rebuilding from scratch when conditions improve.
What’s Realistic for an SME
Illustratively: a UK SME turning over £1–2m per year and looking to grow meaningfully should expect to invest somewhere in the range of £40,000–£120,000 annually in marketing — including agency or consultancy fees, ad spend, tools, and content. This is a wide range because the right number is highly specific to sector, margin, competitive intensity, and growth ambition.
The more useful question isn’t “what’s the typical number?” It’s “what level of investment is required to hit our growth target, and is that investment economically rational given the return?” A consultancy can help you answer that with data rather than benchmarks.
HUDL helps UK SMEs build marketing budgets that are commercially grounded and properly allocated. If you’d like a clear view of what a sensible investment looks like for your business, book a free consultation and we’ll walk through it with you.