To qualify for DLA, your child must pass the disability test(s) (see 9 and 14 below) throughout the three months before their claim. The claim can be made during this 3-month period, but payment will not start until the qualifying period has been served.
SSCBA , Ss.72(2)(a) & 73(9)(a)

Renal dialysis – If your child passed the dialysis test (see 19 below ) during the three months before their claim, they will have served the qualifying period. Spells dialysing at least twice a week in hospital or as an outpatient with help from hospital staff count for this qualifying period.
DLA Regs, reg 7(3)

Linked claims – If your child re-claims DLA within two years of the end of a previous award (or an award of child disability payment), the claims are linked. This means if they have a relapse they don’t have to re-serve the qualifying period. They can get DLA as soon as they re-claim, but only at the previous rate and component. If they qualify for a dif