Using a combining contractor: agree the records first
What to agree with a combining contractor before the machine arrives: whose areas count, whose weights count, and who fills in the paperwork.
· 6 min
The combining itself is the easy part of hiring a contractor. The part that causes friction — sometimes months later — is the records: whose area figure the invoice is based on, whose weights count, and who fills in the passports. All of it is painless to agree in June and miserable to argue about in November, so agree it before the machine arrives.
As a rough guide, contractor combining has been running £35-£50 per acre (£90-£120/ha) in recent seasons, depending on crop, terrain and the kit — typical recent rates, and they vary by region. On 400 acres that's a £14,000-£20,000 invoice, which is exactly why a 5% disagreement about the area is worth heading off in advance.
Whose area figure counts
Most combining is invoiced per acre or per hectare, and the contractor's GPS-derived worked area and your cropped area are not the same number. The machine measures ground the header covered, including overlaps and the odd pass through a grass margin gateway; your RPA maps show the cropped area. A gap of a few percent is normal. On a £16,000 job, a few percent is several hundred pounds.
The fix is boring and effective: before the season, exchange a field list with your cropped areas on it, and agree which figure the invoice follows — usually the cropped area, with the contractor's GPS as a cross-check rather than the billing basis. If a field's area is genuinely uncertain, sort it out now; measuring field area properly is a one-off job that settles every future argument about that field, not just this one.
The classic dispute is the invoice that says 212 acres against RPA maps saying 198. Neither side is lying — they're measuring different things. Agreeing the basis in advance turns that from a row into a footnote.
Whose weights count
If any part of the arrangement touches tonnage — a per-tonne element, a yield-share, or just your own need for honest field yields — decide whose weights are the record. The contractor's yield monitor is an estimate, commonly 3-5% out uncalibrated; weighed loads over a bridge are the truth. If tonnage matters, weighed loads win, and it's worth saying so out loud before anyone quotes the monitor at settlement.
Even on a straight per-acre job, you still want the tonnes recorded — they're your field yields, your shed stock and your marketing position. Which leads to the next item.
Who records the loads — especially if you cart your own
A common split: the contractor cuts, you cart. In that case the load records are entirely your job, and the discipline is the same as any other harvest day — every load tagged with field, crop and destination shed at the time it happens, not reconstructed later. The contractor's machine won't do this for you, and a week of "it's all wheat, it's all going in the big shed" leaves you unable to say what any field did or what's actually in the store.
It's worth being explicit with the contractor's operator about field boundaries too. They don't know that what looks like one 30-hectare block is three fields in your records, and if the carting crew doesn't mark the changeover, that's three field yields collapsed into one average.
Who fills in passports and declarations
Grain passports need post-harvest treatment declarations and store details that the contractor may know nothing about, and pre-harvest declarations (glyphosate use, growth regulators) that only you can sign. Agree who completes what: typically the farmer owns the passport and its declarations, while the contractor provides anything relevant about the combine — not least whether the machine was cleaned down between farms, which matters when the previous job was a different crop or someone else's treated seed.
If you're in an assurance scheme, contractor operations still sit inside your record-keeping obligations — the scheme doesn't care that the combine wasn't yours.
How the disputes actually arise
Not usually from bad faith. From gaps:
| Dispute | Root cause |
|---|---|
| Invoiced area vs cropped area | Basis never agreed; GPS worked area billed against RPA expectations |
| Tonnage claimed vs shed reality | Monitor estimate treated as weights; loads never recorded per field |
| "That field was terrible" with no evidence | Fields not separated in the load records; only a block average exists |
| Passport queries at intake | Nobody owned the declarations; machine hygiene unrecorded |
| Extra charges for laid crop or green straw | Condition never discussed; no note made on the day |
Every row has the same fix: a sentence agreed in June and a record made on the day.
The pre-season agreement list
Ten minutes on the phone or over a kitchen table, ideally in writing — an email both sides keep is plenty:
- Rate and basis — per acre or per hectare, and whose area figure counts.
- The field list, with your cropped areas attached.
- Whose weights are the record, if tonnage matters at all.
- Who carts, and who records each load against field and shed.
- Who completes passports and treatment declarations; machine cleandown confirmed.
- Extras — how laid crop, green patches or chopping-vs-swathing changes are priced.
- Payment terms, and who to ring when something needs deciding mid-field.
None of it is onerous. All of it is easier before the machine is on the pad with 60 hectares fit and rain forecast Thursday.
Frequently Asked Questions
How much does contractor combining cost in the UK?
As a rough guide, £35-£50 per acre (£90-£120/ha) in recent seasons, varying with crop, terrain, straw handling and the machine. Extras like chopping, laid crop or very small fields are often priced separately — ask for the full rate card rather than the headline figure.
Should contractor combining be charged on GPS area or mapped area?
Agree it before the season — that's the real answer. The machine's GPS worked area includes overlaps and typically runs a few percent above the RPA cropped area, so most arrangements bill on the cropped area with GPS as a cross-check. Either basis works; an unagreed basis doesn't.
Who fills in the grain passport when a contractor combines?
Normally the farmer — the passport's declarations cover the crop, its treatments and its storage, which are the grower's knowledge. The contractor's contribution is machine hygiene: confirmation the combine was cleaned down after its previous job, worth asking for and noting.
Do I still need my own harvest records if a contractor cuts the crop?
Yes, arguably more so. The contractor's monitor gives estimates, not weights, and won't split your fields the way your records need. Load-by-load records against field and shed remain your job — they're the basis of your yields, your store contents and your side of any settlement conversation.
Track harvest without the spreadsheet chaos
Harvestt keeps weighbridge loads, shed fill, and field yields in one place.
Get started