The Radius Is a Guess: Target UK Streets, Not Whole Counties

Local targeting has a bad habit of starting with a map and a ruler. Pick a town, draw a 15-mile circle, set the budget, hope for the best. It looks tidy in a planning meeting. It also quietly pays for clicks from people who live near a motorway junction, work on the other side of a river, or would sooner drive to a competitor than battle your one-way system.

The radius is not the problem. The problem is treating a straight-line circle as if it were a real catchment. In the UK, a postcode district is often a better unit of truth than a county line, and a drive-time isochrone is usually more honest than a distance ring. If you run a service business or a small shop, the aim is not to cover more ground. It is to cover the right ground.

A Circle Is Not a Catchment

A 20-mile radius around Leeds city centre includes parts of Bradford, Wakefield and a fair amount of green belt. It does not know that a customer in one direction faces a 40-minute crawl at 8am while someone slightly further away has a clear run. It does not know that your best buyers cluster in three postcode districts and your worst sit right next to the shop.

For a local retailer, the practical catchment is shaped by parking, bus routes, school runs and whether people are willing to carry a purchase home. For a service business, it is shaped by drive time, job value and whether the van can get there without eating the margin. A circle ignores all of that. It is a starting sketch, not a strategy.

Postcode Districts Are the Unit That Pays

You do not need full postcodes to make better decisions. Outward codes are enough for most small teams. LS6, M14, B13, BS3. They give you enough shape to see clusters without turning your customer list into a surveillance project.

Start with the data you already have: orders, bookings, quote requests, enquiries. Export the postcode district for every converted customer over the last six to twelve months. Then group them. Which districts bring volume? Which bring margin? Which produce one big order and then nothing? Which generate leads that never answer the phone?

That is where the useful argument starts. Not 'should we target Manchester?' but 'why are we paying for clicks in M14 when our best jobs come from M20 and M21?' Three streets can outperform three counties. Your job is to find out which three streets.

Drive Time Beats Distance as the Crow Flies

A drive-time isochrone is simply a shape showing how far you can travel in 15, 30 or 45 minutes. It bends around rivers, rail lines, ring roads and the bits of the UK road network that behave like a bad tempered queue. For local service businesses, it is usually a better targeting layer than a radius.

Use it alongside your postcode data. Map your converted customers, then overlay 15, 30 and 45-minute drive-time bands. You will often see a core area where most profitable work sits, a fringe area that is worth testing, and an outer ring that looks close on a map but is a pain in real life.

For shops, the same logic applies with footfall and parking instead of drive time. If your customers come by bus, a 10-minute walk from a stop matters more than a 3-mile radius. If they come by car, the quality of parking and the return trip with a bulky purchase can decide whether they ever come back.

Let Your Own Conversions Redraw the Map

Ad platforms are happy to suggest broad areas because broad areas spend more. Your own conversion data is the antidote. Pull it into a spreadsheet, add the outward code, and calculate conversion rate, cost per acquisition and average margin by district. Do not rely on last-click alone if you can see enquiries or assisted paths. A lead that takes three visits to convert is still a lead.

Then sort by profit, not just revenue. A district with a high average order value but heavy returns may be worse than a modest district with tidy margins. A service area with short drive times may be worth bidding harder on even if the job value is slightly lower. You are looking for repeatable, profitable behaviour, not a heat map that flatters your reach.

Expansion Should Earn Its Place

Once you have a core area, split your campaigns into tiers. Core districts get the higher bids, the tailored copy and the budget protection. Fringe districts get a watchful budget and a stricter CPA target. Experimental districts get a small, time-boxed test, not an open invitation.

Expand only when the margin justifies it. That means setting a floor: if a district cannot hit your target after a fair test, it goes. For e-commerce, remember that delivery cost and returns can turn a distant click into a loss. For service businesses, remember that a 45-minute drive each way can turn a decent job into a poor one.

A Practical Checklist Before the Next Spend Cycle

• Export six to twelve months of converted postcodes and group them by outward code.
• Rank districts by revenue, margin and conversion rate, not just volume.
• Overlay 15, 30 and 45-minute drive-time bands where travel matters.
• Compare your current targeting circle with the map of actual customers.
• Split campaigns into core, fringe and experimental districts.
• Check location settings so you are targeting people in the area, not just people showing interest in it.
• Set separate budgets and CPA targets for each tier.
• Give tests at least 28 days before judging them, and check sample size first.
• Document why each district stays, shrinks or goes.

None of this needs a huge analytics stack. A clean export, a postcode lookup and a mapping tool will get most small UK teams further than another broad radius. The point is not to build a perfect map. It is to build a smaller, more honest one.

A radius is a guess. Your postcode data is evidence. As we head into the final stretch of 2026, with click prices doing what they do, precision is usually cheaper than scale. Draw streets, not counties, and make every mile of targeting earn its place.