Is CIS deducted from retentions?

Is CIS deducted from retentions? Yes, but only when it is paid. As of October 2026, HMRC treats a retention like any other payment: CIS is deducted on the day it is released, at your CIS status on that date. After. CIS applies only to payments actually made, so the contractor deducts from what it pays you now and deducts from the retention only when it releases it. The rate for your CIS status on the date the retention is paid, not when the work was done. If you have gross payment status by then, the retention is paid in full. Possibly. CIS 340 says the contractor must decide at the time of payment whether to verify you. Verification is needed if you have not been on that contractor's return in the current or previous 2 tax years. Read the full answer, with every source, at rightotax.co.uk.