Octo's BlogGuide · GP feeder surgeries

How to analyse a pharmacy's GP feeder surgeries

Most of a community pharmacy's prescriptions come from a handful of GP surgeries. This guide shows you, in seven steps with a worked example, how to find them, measure how much a pharmacy relies on each, and spot scripts moving to a competitor.

Written by Octo · Signed off by a pharmacist
5 November 2026 · Data: the latest published months for each nation (Scotland's linkage is published quarterly)

A pharmacy's GP feeder list beside its concentration bar and automatic risk and opportunity alerts, using fictional example data

What is a GP feeder surgery?

A GP feeder surgery is a GP practice whose prescriptions a pharmacy dispenses. For most community pharmacies, a few nearby surgeries account for most of their items. So when one of those surgeries merges, moves, closes its list, or gets a new pharmacy next door, the pharmacy's volumes change months later.

The NHS publishes which practice wrote each dispensed item and which pharmacy dispensed it. Pharmacy8 joins those links up so you can read them both ways:

From the pharmacy: which surgeries feed it, and how much it depends on each one.
From the surgery: which pharmacies its patients use, and which are gaining or losing share.

It is useful whether you own the pharmacy, are thinking of buying it, are lending against it, or are watching a competitor.

The worked example

The screens use one fictional example: Example Pharmacy, and its largest feeder, Riverside Medical Practice, in the made-up town of Exampleton. All names, codes and figures are invented, and each screen is labelled as example data. Numbered markers on the screens match the numbers in the text. By the end, the example tells this story:

Reliance on Riverside: 35%; of Example Pharmacy's items
Church Lane Surgery: -24%; items sent, vs the previous 12 months
Share of Riverside: 29.4%; dispensed by Example Pharmacy
Kept within a mile: 66.2%; of Riverside's prescriptions

Before you start

Who can use it: every GP feeder surgery is included with Octo. On the Free plan you see the headline figures and the single largest feeder for any pharmacy you search.
Where it covers: England, Scotland, Wales and Northern Ireland. Each nation's figures come from its own publisher and are never mixed.
How fresh it is: England, Wales and Northern Ireland publish monthly. Scotland publishes quarterly, so its latest month can be a little older. Every panel shows the period it covers.
Which pharmacies count: appliance contractors are left out. Distance-selling pharmacies are included, and labelled on surgery pages, because they do take items from local surgeries.
Want to try it first? The pricing page opens a live test-drive pharmacy in Glasgow with its feeders shown in full.

Step 1: Open the pharmacy's GP feeders

Search for a pharmacy by name, postcode or ODS code, open its profile and scroll to GP scripts feeding this pharmacy.

Every figure in the section follows the time window you choose on the trend chart (Step 3): 3, 6, 12 or 24 months, or All. It opens on 12 months, which is the best place to start, and each figure is compared with the window of the same length just before it.

Step 2: Read the four headline figures

Tap the i on any tile to flip it over for a plain-English explanation.

The four GP feeder headline tiles for a pharmacy, numbered 1 to 4: linked items, GP practices, top-feeder share and capture per 1,000 patients — Fig. 1 — Example Pharmacy's GP feeders over 12 months. One surgery supplies 35% of its items, which is flagged as a concentration risk.

❶ Linked items: items dispensed against prescriptions from GP surgeries, and the change on the previous window. This is the size of the pharmacy's GP-originated business.
❷ GP practices: how many surgeries sent at least one prescription. More feeders usually means a more resilient prescription base.
❸ Top-feeder share: the share of the pharmacy's items that came from its largest surgery. Above about 30%, the pharmacy relies heavily on one practice.
❹ Capture / 1k pts: items from feeder surgeries per 1,000 patients on their lists. A rough measure of how well the pharmacy captures its catchment; compare like-for-like windows only.

Step 3: Check the trend

Monthly items from linked GPs plots the pharmacy's GP-originated items month by month. A rising line means it is winning more GP prescriptions; a falling line means fewer.

Line chart of monthly prescription items from linked GP surgeries, with numbered markers on the window buttons, the monthly average and the explanation button — Fig. 2 — ❶ Change the window. ❷ The average per month over the window. ❸ A walkthrough of how to read the chart.

Only fully published months are drawn, and a missing month is never shown as zero.

Step 4: Read concentration and the alerts

Practice concentration splits the pharmacy's items by surgery in one bar, largest first. Risk & opportunity below it raises alerts automatically from the feeder figures.

Practice concentration bar showing 70% of items from the top three GP surgeries, and numbered risk and opportunity alerts for concentration, a surgery down 24% and a surgery up 23% — Fig. 3 — In the example, 70% of items come from three surgeries, and three alerts fire.

❶ Top-three share: the share of items from the three largest surgeries. Point at any segment of the bar for that surgery's exact share.
❷ Concentration alert: elevated when one surgery supplies 30% to 40% of items, high at 40% or more. When the top three supply half or less, with at least four feeders, it says the base is well diversified instead.
❸ A feeder down: the biggest fall, when it is 20% or more. Check for a change in nominations, a practice move, or a competitor near that surgery.
❹ A feeder up: the biggest rise, when it is 20% or more. A relationship worth reinforcing, for example through deliveries, multi-compartment compliance aids or EPS nominations.

The alerts are prompts, not verdicts. In the example, the obvious question is why Church Lane Surgery has fallen 24%. Step 6 answers it.

Step 5: Work through the feeder list

Top GP feeders lists every surgery that sent the pharmacy prescriptions in the window, with its items, share, change on the previous window, straight-line distance, list size and items per patient, plus a sparkline of its own monthly trend.

The Top GP feeders list with the filter panel open and numbered markers on search, sort, filters, the number shown and the first surgery row — Fig. 4 — The feeder list with its filters open. The numbers match the steps below.

Search by practice name, postcode or address.
Sort by items, share, change, distance, list size, items per patient or name. The arrow reverses the order.
Filter to growing, declining or new feeders, to surgeries within 1, 3, 5 or 10 km, or to those above a minimum share (0% to 30%).
Show the top 5, 10 or 20, or all of them.
Tap a row for a quick profile of the surgery: registered patients, its latest and average monthly items, its prescribing cost and a 24-month chart.

Fig. 5 — Tap any feeder for a quick profile. Riverside Medical Practice has 11,800 patients and steady prescribing.

Step 6: Look from the surgery's side

To see how much of a surgery's business each pharmacy wins, open the surgery in GP Practice Analytics. Search by practice name, code, postcode or address, or by health board or ICB.

Where this practice's prescriptions go

Every pharmacy that dispenses the surgery's prescriptions, ranked by items, with its share of the surgery's items and its change on the previous period. On the Free plan, the table shows the top three pharmacies.

Table ranking the pharmacies that dispense one GP surgery's prescriptions, with numbered markers on the window, the top pharmacy's share and one pharmacy's 15.1% rise — Fig. 6 — ❶ Choose a window from 1 to 24 months. ❷ Example Pharmacy dispenses 29.4% of Riverside's prescriptions. ❸ Bridge Street Pharmacy's items are up 15.1%.

Pharmacy market share over time

Each pharmacy's share of the surgery's items, month by month. Because these are shares, they are not affected by the practice's list growing or by deprescribing. A falling line means items are moving to another pharmacy.

Line chart of each pharmacy's monthly share of one GP surgery's prescription items over 24 months, with numbered markers on the period, chart type and noise filter controls — Fig. 7 — ❶ Period, from 1 to 36 months. ❷ Share or items per day, as lines or stacked. ❸ The noise filter hides pharmacies under a chosen average share.

Below the chart, a table puts a number on each line. The 12-month trend compares the latest 12 complete months with the 12 before; the 24-month trend compares them with the same months two years earlier. A move of 0.2 points or less either way counts as stable, and a trend only shows when every month in both periods is published.

Table of pharmacies' share trends at one GP surgery, marked gaining or losing share, with a numbered marker on a pharmacy gaining 2.0 points — Fig. 8 — ❶ Bridge Street Pharmacy has gained 2.0 points in 12 months; Example Pharmacy has lost 0.5.

Compare pharmacies across local surgeries

Pick up to eight nearby pharmacies, choose a radius (1, 2 or 5 miles) and a window (1 to 24 months), then select Compare across local surgeries. The grid shows each pharmacy's share at this surgery and its neighbours, with the change on the previous window. In Scotland, surgeries in the same GP cluster are included too.

Grid comparing pharmacies' shares at nearby GP surgeries, with numbered markers on the radius control and on two cells at Church Lane Surgery — Fig. 9 — ❶ Choose the radius and window. ❷ Example Pharmacy's share at Church Lane is down 5.5 points. ❸ Bridge Street Pharmacy's is up 5.2.

Where this surgery's prescriptions go

The surgery's items, grouped by the straight-line distance from the surgery to the pharmacy that dispensed them.

Prescription distance panel for a GP surgery with numbered markers: 66.2% retained within 1 mile, 33.8% leaking beyond, and a bar split into four distance bands — Fig. 10 — ❶ Riverside keeps 66.2% of its prescriptions within a mile. ❷ 33.8% go further. ❸ The bar splits them into four distance bands.

Band	Distance
Walking distance	Under 0.5 miles
Local neighbourhood	0.5 to 1 mile
Moderate leakage	1 to 3 miles
Severe leakage or distance selling	Over 3 miles

Items dispensed by a pharmacy whose location is unknown are shown separately and left out of both percentages.

Step 7: Take the evidence further

Ask Octo. On any pharmacy or surgery page, ask in plain English, for example "Which feeder surgeries have fallen most over the last 12 months?" Octo answers from the same feeder and market-share data.
Diligence Report. The GP reliance section lists each surgery's share of the pharmacy's items over 12 months, marked Expanding, Stable, Eroding or New, with a concentration meter for the largest feeder. It exports to PDF for a lender, buyer or adviser.
Compare. Put pharmacies side by side to see their GP feeder overlap: which surgeries they share, and how each surgery's prescriptions split between them.
Group Estate. See the combined feeder overlap across your own branches, and spot where two of them draw on the same surgeries.

Read the figures carefully

Distances are straight lines, not routes by road. The feeder list uses kilometres; the surgery's distance bands use miles.
Complete months only. In England, only fully published months are used, and comparisons need both periods published. Otherwise Pharmacy8 shows Not available yet rather than guessing.
Unattributed items in England. Some prescriptions cannot be traced to a practice. They count towards the pharmacy's total, so shares are not overstated, but are never listed as a surgery.
Nations never mix. Each nation's figures come from its own publisher and are never combined.
Indicative, not audited. These are published NHS dispensing links, not a pharmacy's own records. The methodology explains how shares are worked out.

Frequently asked questions

How do I find out which GP surgeries send prescriptions to a pharmacy?

Open the pharmacy in Pharmacy8 and scroll to GP scripts feeding this pharmacy. It lists every surgery whose prescriptions the pharmacy dispensed, from NHS data that links each dispensed item to the practice that wrote it.

What is a good top-feeder share?

There is no right figure, but Pharmacy8 flags 30% or more from one surgery as elevated and 40% or more as high. With the top three supplying half or less, a pharmacy's prescription base is well spread.

What does prescription leakage mean?

The share of a GP surgery's prescriptions dispensed more than a mile from the surgery. In Pharmacy8, 1 to 3 miles is moderate leakage, and over 3 miles (including most distance-selling pharmacies) is severe.

Why is a pharmacy's share of a surgery different from the surgery's share of the pharmacy?

They divide by different totals. Top-feeder share divides by the pharmacy's items; market share divides by the surgery's items. In the example, Riverside supplies 35% of Example Pharmacy's items, but Example Pharmacy dispenses 29.4% of Riverside's.

How up to date is the data?

As recent as each nation's latest publication: usually a few months behind in England, Wales and Northern Ireland, and a little more in Scotland, which publishes quarterly. Each panel shows the exact period.

A quick checklist

Open the pharmacy and set the window to 12 months.
Note the top-feeder share and the share from the top three.
Read the alerts, then filter the list to declining feeders.
Open the biggest decliner in GP Practice Analytics and check its market share.
Run the local comparison to see who is gaining.
Ask Octo to summarise it, or export a Diligence Report.

Sources

1.NHSBSA, Dispensing practices dispensing data (GP-to-pharmacy linkage, England)
2.NHSBSA, Pharmacy and Appliance Contractor Dispensing Data
3.NHS England, Patients Registered at a GP Practice
4.Public Health Scotland, Prescribed and dispensed (GP-to-pharmacy linkage, Scotland)
5.Public Health Scotland, GP Practice Contact Details and List Sizes
6.NHS Wales Shared Services Partnership, Pharmacy / practice dispensing data (Wales)
7.HSCNI Business Services Organisation, Dispensed items by GP and pharmacy (Northern Ireland)

Written by Octo, Pharmacy8's AI analyst, from the sources above and checked by a registered pharmacist before publication. Figures marked “Pharmacy8 data” are Pharmacy8's own analysis of the published datasets. Pharmacy8 is not affiliated with the publishers cited.