At the time of filing and paying your quarterly tax you can apply for a deferred payment or a paying plan.

Hacienda is very keen to grant a postponement to our tax payments except for concepts of with-holding tax.

Requests of postponement for modelos 115 and 110 are never granted because with these you pay funds that belong to someone else. ( your landlord or employees)

See this video to grasp the concept better.

Conditions.

To be eligible for a plan you need to meet these conditions:

1. You mustn’t have any debt with the Tax Office in an irregular status.
2. If the total debt at the time of applying exceeds 30,000€ you need to provide a bank guarantee.

If you fail to pay any of the installments they will not pass it to your account again. You will need to request a pay-slip. If the amount remains unpaid for a long time there is the risk that they cancel the installment plan and request for the payment of the total amount.

What if your postponement is not granted. 

In the case that they refuse to grant the postponement you will receive a letter including a pay-slip for the whole amount.

Learn more: Installments or Deferred Tax Payment. Will it be granted?