De haber acreditado la compra, habría solicitado el desistimiento.

It is a conditional clause without si.

A more expanded version would be:

• Si hubiera/hubiese acreditado la compra, habría solicitado el desistimiento.

So de + infinitive can introduce a condition, especially in formal or written Spanish. When the condition refers to an unreal past situation, Spanish often uses:

• de haber + past participle

Here:

• haber acreditado = to have proved / to have provided proof of
• de haber acreditado = if (someone) had proved / provided proof

This structure is much more formal than what many learners first see with si.

After de in this structure, Spanish uses the infinitive perfect:

• haber + past participle

So:

• de haber acreditado = if ... had provided proof

You do not use a finite verb form like:

• de había acreditado ❌
• de hubiera acreditado ❌

Those finite forms would be used in a clause with si, not after de:

• Si hubiera acreditado la compra... ✅

So the contrast is:

• de haber acreditado... = formal infinitive construction
• si hubiera acreditado... = standard finite conditional clause

Yes, in meaning they are essentially the same here.

Both express an unreal condition in the past:

• De haber acreditado la compra, habría solicitado el desistimiento.
• Si hubiera acreditado la compra, habría solicitado el desistimiento.

The difference is mainly style/register:

• de haber acreditado... = more formal, more common in legal, administrative, or written contexts
• si hubiera acreditado... = more neutral and common in everyday grammar explanations

So a native speaker would understand both, but the version with de haber sounds more official.

Because the sentence describes a past unreal result.

This is the Spanish equivalent of a pattern like:

• If X had happened, Y would have happened.

For that kind of idea, Spanish typically uses:

• unreal past condition
  • conditional perfect

So:

• habría solicitado = would have requested / would have applied for

This tense is the conditional perfect:

• haber in the conditional (habría) + past participle (solicitado)

It shows that the action did not actually happen, but would have happened under a different condition.

This is a past unreal conditional (sometimes called a third conditional in English-style grammar terminology).

Its basic meaning is:

• The condition did not happen.
• Therefore, the result did not happen either.

In more standard textbook form, the pattern is:

• Si + pluperfect subjunctive, + conditional perfect

Example:

• Si hubiera acreditado la compra, habría solicitado el desistimiento.

Your sentence uses the more formal alternative:

• De haber acreditado la compra, habría solicitado el desistimiento.

So grammatically it still belongs to the same past counterfactual type.

Here acreditar does not mean the same thing as the common English use of accredit.

In this context, acreditar means:

• to prove
• to demonstrate
• to provide evidence of
• to document

So acreditar la compra means something like:

• to prove the purchase
• to provide proof of purchase

For example, that might mean showing:

• a receipt
• an invoice
• a confirmation email
• other documentation

This is a good example of a word that can look familiar to an English speaker but is used differently in Spanish.

Spanish often uses the definite article where English may not.

Here la compra refers to a specific purchase already understood from the context:

• the purchase
• that purchase

In administrative or legal language, this is very normal:

• acreditar la compra
• justificar el pago
• presentar la factura

English often drops the article in similar phrases, but Spanish commonly keeps it.

Desistimiento is a formal/legal noun. In Spain, it is especially common in consumer law.

It usually refers to:

• withdrawal
• cancellation
• the right to withdraw from a purchase/contract

In many consumer contexts in Spain, you will see expressions like:

• derecho de desistimiento = right of withdrawal
• ejercer el desistimiento = to exercise the right of withdrawal

So this is not everyday casual vocabulary. It belongs to a more official register.

It is understandable, but it sounds quite formal and somewhat administrative/legal.

Depending on the exact context, Spanish in Spain might more naturally say:

• ejercer el derecho de desistimiento
• solicitar la cancelación
• pedir la devolución
• tramitar el desistimiento

If the context is specifically the legal right of withdrawal in a consumer transaction, desistimiento is correct. However, many speakers would expect a phrase like:

• habría ejercido el derecho de desistimiento

rather than habría solicitado el desistimiento, because desistimiento is often treated as a right you exercise, not just something you request.

So the original sentence is possible, but it has a distinctly official tone.

The subject is omitted, which is very normal in Spanish.

From habría solicitado, we know the subject is a singular person, depending on context:

• yo = I would have requested
• él/ella/usted = he/she/you would have requested

Spanish often leaves out subject pronouns because the verb ending already gives enough information.

Without context, the sentence is ambiguous about exactly who the subject is. Context would tell you whether it means:

• I would have requested...
• he/she would have requested...
• you (formal) would have requested...

Yes. The clause with de haber acreditado la compra can go first or second.

For example:

• De haber acreditado la compra, habría solicitado el desistimiento.
• Habría solicitado el desistimiento de haber acreditado la compra.

Both are grammatical.

Putting the condition first is often clearer and is very common in formal writing. The comma is also typical when that conditional phrase comes first.

Usually, no—not in ordinary casual conversation.

It sounds more like:

• a complaint letter
• a legal statement
• customer service correspondence
• administrative writing

In everyday speech, many people would be more likely to say something like:

• Si hubiera podido demostrar la compra, habría pedido la devolución.
• Si hubiera tenido el justificante, habría cancelado la compra.

So the original sentence is grammatically fine, but it belongs to a formal, bureaucratic, or legal register.

It refers to a situation in the past that did not happen.

The structure tells us:

1. In the past, the person did not accredit/prove the purchase.
2. As a result, they did not request the withdrawal/cancellation.

So both parts point to an imagined alternative past.

That is why Spanish uses:

• de haber acreditado = unreal past condition
• habría solicitado = unreal past result

This is not about a real possibility in the present; it is about what would have happened differently in the past.