Across:
8 American neighbour (CANADA) produced a (-A-) new (-N-) commercial (-AD-) welcomed by accountant (CA = C-A) (CANADA),
9 They market what’s in 15 across (INSURERS market ‘insurance policy’) to risk-takers (INSURERS),
10 Left (l) out of retrograde (= reverse indicator) medication (pills) (‘pills’ without ‘l’ = SLIP) for trip (SLIP),
11 Workers (M-EN) getting to grips with donations (-AID-) from celebrity (NAME) (MAIDEN NAME) coming out of wife’s previous address (MAIDEN NAME),
12 Without the borders (l-y), this is staggering (lurching) (without the borders ‘LurchinG’ = URCHIN) to young one on the street (URCHIN),
14 Esther edges away (‘e’ + ‘r’) (‘EstheR’ without ‘er’ = STHE-) after (= position indicator) Russell (AE- Russell) finds Lawrence (-TE Lawrence) (AESTHETE) is sensitive to arty types (AESTHETE),
15 Get out of jail card (INSURANCE POLICY) – presumably that’s only for the one undercover with the car (INSURANCE POLICY),
18 Matches a (matches a) set (= anagram indicator) (matches a = SCHEMATA) of plans (SCHEMATA),
20 Aristotle dismisses art (‘Aristotle’ dismisses ‘art’ = isotle = LOSE IT) with crack? (LOSE IT),
22 Covers (INSURANCES) start of 15 across (start of ‘insurance policy’ = INSURANCE-) at school (S-) (INSURANCES),
24 The latest rage (MODE) for somebody with no boys? (‘somebody’ with no ‘boys’ = omed = MODE),
25 Tip off (r) of reduced sentence (remission) (‘remission’ without ‘r’ = EMISSION) is leaked perhaps? (EMISSION),
26 You’re unlikely to hear this praise if you’re late (EULOGY), as typically it accompanies a put down (EULOGY).
Down:
1 Man of the cloth (TAILOR) produces nothing (-O-) in criminal (= anagram indicator) trial (trial = TAIL-R) (TAILOR),
2 Shines a light (LAMP) on the extremes of labour camp (on the extremes of ‘LAbour caMP’ = LAMP),
3 The Animals’ set opens (‘The Animals Set’ opens = TAS-) to hysteria (-MANIA) (TASMANIA) in Australian state (TASMANIA),
4 Ambition to dispose of boat (‘ambition’ to dispose of ‘boat’ = miin = MINI) with motor (MINI),
5 Those doing a bit of dealing (pushers) lose head (p) (‘pushers’ without ‘p’ = USHERS) with those working in the house (USHERS working in The House/Dáil),
6 The range of Italian neighbours (FRENCH ALPS), in a manner of speaking (FRENCH), with a chain in Switzerland? (ALPS) (FRENCH ALPS),
7 Police department (CID) shows up (= reverse indicator) (CID = D-IC) surrounding a mart (a mart) masquerading (= anagram indicator) (a mart = -RAMAT-) (DRAMATIC) as something theatrical (DRAMATIC),
13 Party leader (host = HO -ST) goes around America (-US-), for example, (e.g. = -E G-) and European Union (EU) upsetting (= reverse indicator) (EU = -UE-) (HOUSE GUEST) one of those asking to stay at home (HOUSE GUEST),
14 Away (A-) at college (-C-) on rebellious (= reverse indicator) curve (arc = -CRA) (ACCRA) in Ghana, they serve you this fritter to eat? (ACCRA = a fritter eaten in Africa and the Caribbean; and also the capital of Ghana),
16 Steal (NICK -) someone’s identity (-NAME) (NICKNAME) or familiar moniker (NICKNAME),
17 A job for one taking a shine to some (POLISHER) perfect (perfect/refine = POLISH-) leaders of Easter Rising (leaders of ‘Easter Rising’ = -ER) (POLISHER),
19 Turns off graduations (‘turns’ off ‘graduations’ = gadaio = ADAGIO) – is it the slow tempo? (ADAGIO),
21 One (I-) doing (doing = -NDIGO) work (= anagram indicator) (INDIGO) out of the blue? (INDIGO),
23 Downsides (CONS) when there’s a lot missing from coolants (when there’s ‘a lot’ missing from ‘coolants’ = cons = CONS),
24 Son (MALE) of revolutionary (= reverse indicator) characters taken in by Angela Merkel (characters taken in by ‘angELA Merkel’ = elam = MALE).