Tree work is short, self-contained and materials-light, which puts it at the low-risk end for payment arrangements.
The normal pattern
Most domestic tree jobs are done in a day or two and invoiced on completion. Unlike a builder, a tree surgeon is not buying thousands of pounds of materials on your behalf, so there is little reason to ask you to fund the job in advance.
If someone wants full payment before a one-day job, that is unusual and worth questioning.
When a deposit is reasonable
Two situations genuinely justify one.
Booked-in costs. Where the job needs a parking bay suspension, a road closure, a traffic management plan or hired plant such as a crane or mobile elevating platform, those are paid for in advance and are not refundable if you cancel. A deposit covering them is fair.
Large or multi-day contracts. A week of work across a large garden reasonably attracts a stage payment.
In both cases the deposit should relate to identifiable costs, not simply be a percentage of the total.
Check before you pay
Tree work is easy to inspect and hard to fix afterwards, so do it before the crew leaves.
Walk the site. Confirm the work matches what was specified: the right tree, the right reduction, the right branches. If you asked for a two-metre crown reduction, look at whether that is what you have got.
Check the cuts. Proper pruning cuts are made just outside the branch collar, the slight swelling where a branch meets the stem, leaving a clean surface. Torn bark, ragged edges, long stubs or flush cuts into the trunk are poor work and will cause decay.
Check the site is clear. Confirm what was agreed about waste, whether it was taken away, chipped, or stacked.
Check the stump if stump removal was included, and confirm the grinding depth.
Cash and invoices
Paying cash is legal and many small firms prefer it. But get an invoice regardless of how you pay.
Without one you have no record of the contract, the price or the date, which matters if the tree later fails and there is an argument about what was done. It also matters for an insurance claim, where the insurer will want documentation of the work.
A discount specifically conditional on there being no paperwork is usually about tax rather than saving you money, and it removes your evidence.
Keep the paperwork
For tree work more than most trades, the paper record has lasting value.
If the tree was protected, keep the council consent or the section 211 notice acknowledgement. If a neighbour later queries the work, or you sell the house, that is the document that shows it was lawful.
If the work relates to a subsidence claim, your insurer will want the arboricultural report, the consent and the contractor's invoice.
And if a tree you had assessed subsequently fails and damages something, evidence that you commissioned a qualified contractor who inspected it is what demonstrates you took reasonable care.
Guarantees
There is little to guarantee in tree work, since it is a one-off operation rather than an installation. What matters instead is that the contractor was insured and competent at the time, which is why the checks before booking matter more than any promise afterwards.